422 lines
17 KiB
Text
422 lines
17 KiB
Text
#
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# SURFACE MECHANISM OF POX of CH4 on PT wire gauze
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#
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#***********************************************************************
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#**** *
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#**** CH4-O2 SURFACE MECHANISM ON PT *
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#**** *
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#**** Version 1.0 Spring 2005 *
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#**** *
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#**** Raul Quiceno, Olaf Deutschmann, IWR, Heidelberg University, *
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#**** Germany *
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#**** Contact: mail@detchem.com (O. Deutschmann) *
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#**** *
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#**** Reference: *
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#**** R. Quiceno, J. Perez-Ramyrez, J. Warnatz, O. Deutschmann. *
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#**** Appl. Catal. A: General (2006) *
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#**** www.detchem.com/mechanisms *
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#**** *
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#**** *
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#**** The kinetic data of the backward reactions of *
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#**** reactions in Section 3 are calculated *
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#**** from thermodynamics (k_b = k_f /K) *
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#**** *
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#**** Surface site density: 2.72E-9 mol/cm**2 *
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#**** *
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#----------------------------------------------------------------------
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units(length = "cm", time = "s", quantity = "mol", act_energy = "J/mol")
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#
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# Define a gas mixture. This contains only major species, and no
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# gas-phase reactions.
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#
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ideal_gas(name = "gas",
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elements = "O H C N Ar",
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species = """H2 O2 H2O CH4 CO CO2 AR""",
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options = ['skip_undeclared_elements',
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'skip_undeclared_species'],
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initial_state = state(temperature = 300.0, pressure = OneAtm,
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mole_fractions = 'CH4:0.095, O2:0.21, AR:0.79')
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)
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#
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# The platinum surface.
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ideal_interface(name = "Pt_surf",
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elements = " Pt H O C ",
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species = """ PT(S) H(S)
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H2O(S) OH(S) CO(S) CO2(S) CH3(S)
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CH2(S) CH(S) C(S) O(S) """,
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phases = "gas",
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site_density = 2.72e-9,
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reactions = "all",
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options = ['skip_undeclared_elements',
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'skip_undeclared_species'],
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initial_state = state(temperature = 900.0,
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coverages = 'O(S):0.00, PT(S):0.01, H(S):0.99')
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)
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#-------------------------------------------------------------------------------
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# Species data
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#-------------------------------------------------------------------------------
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species(name = "CH4",
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atoms = " C:1 H:4 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 7.787414790E-01, 1.747668350E-02,
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-2.783409040E-05, 3.049708040E-08, -1.223930680E-11,
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-9.825228520E+03, 1.372219470E+01] ),
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NASA( [ 1000.00, 5000.00], [ 1.683478830E+00, 1.023723560E-02,
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-3.875128640E-06, 6.785584870E-10, -4.503423120E-14,
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-1.008078710E+04, 9.623394970E+00] )
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)
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)
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species(name = "O2",
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atoms = " O:2 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 3.783713500E+00, -3.023363400E-03,
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9.949275100E-06, -9.818910100E-09, 3.303182500E-12,
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-1.063810700E+03, 3.641634500E+00] ),
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NASA( [ 1000.00, 5000.00], [ 3.612213900E+00, 7.485316600E-04,
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-1.982064700E-07, 3.374900800E-11, -2.390737400E-15,
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-1.197815100E+03, 3.670330700E+00] )
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)
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)
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species(name = "CO",
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atoms = " C:1 O:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 3.262451650E+00, 1.511940850E-03,
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-3.881755220E-06, 5.581944240E-09, -2.474951230E-12,
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-1.431053910E+04, 4.848896980E+00] ),
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NASA( [ 1000.00, 5000.00], [ 3.025078060E+00, 1.442688520E-03,
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-5.630827790E-07, 1.018581330E-10, -6.910951560E-15,
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-1.426834960E+04, 6.108217720E+00] )
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)
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)
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species(name = "CO2",
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atoms = " C:1 O:2 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 2.275724650E+00, 9.922072290E-03,
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-1.040911320E-05, 6.866686780E-09, -2.117280090E-12,
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-4.837314060E+04, 1.018848800E+01] ),
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NASA( [ 1000.00, 5000.00], [ 4.453622820E+00, 3.140168730E-03,
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-1.278410540E-06, 2.393996670E-10, -1.669033190E-14,
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-4.896696090E+04, -9.553958770E-01] )
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)
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)
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species(name = "H2",
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atoms = " H:2 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 3.355351400E+00, 5.013614400E-04,
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-2.300690800E-07, -4.790532400E-10, 4.852258500E-13,
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-1.019162600E+03, -3.547722800E+00] ),
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NASA( [ 1000.00, 5000.00], [ 3.066709500E+00, 5.747375500E-04,
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1.393831900E-08, -2.548351800E-11, 2.909857400E-15,
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-8.654741200E+02, -1.779842400E+00] )
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)
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)
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species(name = "H2O",
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atoms = " H:2 O:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 4.167723400E+00, -1.811497000E-03,
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5.947128800E-06, -4.869202100E-09, 1.529199100E-12,
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-3.028996900E+04, -7.313547400E-01] ),
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NASA( [ 1000.00, 5000.00], [ 2.611047200E+00, 3.156313000E-03,
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-9.298543800E-07, 1.333153800E-10, -7.468935100E-15,
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-2.986816700E+04, 7.209126800E+00] )
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)
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)
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species(name = "AR",
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atoms = " Ar:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 2.500000000E+00, 0.000000000E+00,
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0.000000000E+00, 0.000000000E+00, 0.000000000E+00,
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-7.453749800E+02, 4.366000600E+00] ),
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NASA( [ 1000.00, 5000.00], [ 2.500000000E+00, 0.000000000E+00,
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0.000000000E+00, 0.000000000E+00, 0.000000000E+00,
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-7.453750200E+02, 4.366000600E+00] )
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)
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)
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species(name = "PT(S)",
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atoms = " Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 0.000000000E+00, 0.000000000E+00,
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0.000000000E+00, 0.000000000E+00, 0.000000000E+00,
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0.000000000E+00, 0.000000000E+00] ),
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NASA( [ 1000.00, 3000.00], [ 0.000000000E+00, 0.000000000E+00,
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0.000000000E+00, 0.000000000E+00, 0.000000000E+00,
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0.000000000E+00, 0.000000000E+00] )
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)
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)
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species(name = "H(S)",
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atoms = " H:1 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ -1.302987700E+00, 5.417319900E-03,
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3.127797200E-07, -3.232853300E-09, 1.136282000E-12,
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-4.227707500E+03, 5.874323800E+00] ),
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NASA( [ 1000.00, 3000.00], [ 1.069699600E+00, 1.543223000E-03,
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-1.550092200E-07, -1.657316500E-10, 3.835934700E-14,
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-5.054612800E+03, -7.155523800E+00] )
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)
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)
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species(name = "H2O(S)",
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atoms = " O:1 H:2 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ -2.765155300E+00, 1.331511500E-02,
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1.012769500E-06, -7.182008300E-09, 2.281377600E-12,
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-3.639805500E+04, 1.209814500E+01] ),
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NASA( [ 1000.00, 3000.00], [ 2.580305100E+00, 4.957082700E-03,
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-4.689405600E-07, -5.263313700E-10, 1.199832200E-13,
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-3.830223400E+04, -1.740632200E+01] )
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)
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)
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species(name = "OH(S)",
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atoms = " O:1 H:1 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ -2.034088100E+00, 9.366268300E-03,
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6.627521400E-07, -5.207488700E-09, 1.708873500E-12,
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-2.531994900E+04, 8.986318600E+00] ),
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NASA( [ 1000.00, 3000.00], [ 1.824997300E+00, 3.250156500E-03,
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-3.119754100E-07, -3.460320600E-10, 7.917147200E-14,
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-2.668549200E+04, -1.228089100E+01] )
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)
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)
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species(name = "CO(S)",
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atoms = " C:1 O:1 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 4.890746600E+00, 6.813423500E-05,
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1.976881400E-07, 1.238866900E-09, -9.033924900E-13,
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-3.229783600E+04, -1.745316100E+01] ),
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NASA( [ 1000.00, 3000.00], [ 4.708377800E+00, 9.603729700E-04,
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-1.180527900E-07, -7.688382600E-11, 1.823200000E-14,
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-3.231172300E+04, -1.671959300E+01] )
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)
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)
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species(name = "CO2(S)",
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atoms = " C:1 O:2 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 4.690000000E-01, 6.266200000E-03,
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0.000000000E+00, 0.000000000E+00, 0.000000000E+00,
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-5.045870000E+04, -4.555000000E+00] ),
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NASA( [ 1000.00, 3000.00], [ 4.690000000E-01, 6.266000000E-03,
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0.000000000E+00, 0.000000000E+00, 0.000000000E+00,
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-5.045870000E+04, -4.555000000E+00] )
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)
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)
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species(name = "CH3(S)",
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atoms = " C:1 H:3 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 1.291921700E+00, 7.267560300E-03,
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9.817947600E-07, -2.047129400E-09, 9.083271700E-14,
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-2.574561000E+03, -1.198303700E+00] ),
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NASA( [ 1000.00, 3000.00], [ 3.001616500E+00, 5.408450500E-03,
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-4.053805800E-07, -5.342246600E-10, 1.145188700E-13,
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-3.275272200E+03, -1.096598400E+01] )
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)
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)
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species(name = "CH2(S)",
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atoms = " C:1 H:2 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ -1.487640400E-01, 5.139628900E-03,
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1.121107500E-06, -8.275545200E-10, -4.457234500E-13,
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1.087870000E+04, 5.745188200E+00] ),
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NASA( [ 1000.00, 3000.00], [ 7.407612200E-01, 4.803253300E-03,
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-3.282563300E-07, -4.777978600E-10, 1.007345200E-13,
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1.044375200E+04, 4.084208600E-01] )
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)
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)
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species(name = "CH(S)",
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atoms = " C:1 H:1 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 8.415748500E-01, 1.309538000E-03,
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2.846457500E-07, 6.386290400E-10, -4.276665800E-13,
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2.233280100E+04, 1.145230500E+00] ),
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NASA( [ 1000.00, 3000.00], [ -4.824247200E-03, 3.044623900E-03,
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-1.606609900E-07, -2.904170000E-10, 5.799992400E-14,
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2.259521900E+04, 5.667781800E+00] )
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)
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)
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species(name = "C(S)",
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atoms = " C:1 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ 5.892401900E-01, 2.501284200E-03,
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-3.422949800E-07, -1.899434600E-09, 1.019040600E-12,
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1.023692300E+04, 2.193701700E+00] ),
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NASA( [ 1000.00, 3000.00], [ 1.579282400E+00, 3.652870100E-04,
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-5.065767200E-08, -3.488485500E-11, 8.808969900E-15,
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9.953575200E+03, -3.024049500E+00] )
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)
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)
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species(name = "O(S)",
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atoms = " O:1 Pt:1 ",
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thermo = (
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NASA( [ 300.00, 1000.00], [ -9.498690400E-01, 7.404230500E-03,
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-1.045142400E-06, -6.112042000E-09, 3.378799200E-12,
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-1.320991200E+04, 3.613790500E+00] ),
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NASA( [ 1000.00, 3000.00], [ 1.945418000E+00, 9.176164700E-04,
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-1.122671900E-07, -9.909962400E-11, 2.430769900E-14,
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-1.400518700E+04, -1.153166300E+01] )
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)
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)
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#-------------------------------------------------------------------------------
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# Reaction data
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#-------------------------------------------------------------------------------
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# Adsorption reactions
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surface_reaction("H2 + 2 PT(S) => 2 H(S)",
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stick(0.046, 0, 0,
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coverage = ['PT(S)',0.0, -1.0, 0.0]))
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surface_reaction( "O2 + 2 PT(S) => 2 O(S)",
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Arrhenius(1.89000E+21, -0.5, 0))
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surface_reaction( "CH4 + 2 PT(S) => CH3(S) + H(S)",
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stick(0.0009, 0.0, 72000.0))
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surface_reaction( "CH4 + PT(S) + O(S) => CH3(S) + OH(S)",
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Arrhenius(5.0e18, 0.7, 42000.0,
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coverage = ['O(S)', 0.0, 0.0, 8000]))
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surface_reaction( "CH4 + PT(S) + OH(S) => CH3(S) + H2O(S)",
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stick(1.0, 0.0, 10000.0))
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surface_reaction( "H2O + PT(S) => H2O(S)",
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stick(7.50000E-01, 0, 0))
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surface_reaction( "CO2 + PT(S) => CO2(S)",
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stick(0.005, 0, 0))
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surface_reaction( "CO + PT(S) => CO(S)",
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stick(0.84, 0, 0))
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# Desorption reactions
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surface_reaction( "2 H(S) => H2 + 2 PT(S)",
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Arrhenius(3.70000E+21, 0, 67400,
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coverage = ['H(S)', 0.0, 0.0, -10000.0]))
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surface_reaction( "2 O(S) => O2 + 2 PT(S)",
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Arrhenius(3.70000E+21, 0, 235500,
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coverage = ['O(S)', 0.0, 0.0, -188300.0]) )
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surface_reaction( "H2O(S) => H2O + PT(S)", [4.50000E+12, 0, 41800])
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surface_reaction( "CO(S) => CO + PT(S)",
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Arrhenius(1.00000E+15, 0, 146000,
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coverage = ['CO(S)', 0.0, 0.0, -33000.0]))
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surface_reaction( "CO2(S) => CO2 + PT(S)", [1.00000E+13, 0, 27100])
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# surface reactions
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surface_reaction( "C(S) + O(S) => CO(S) + PT(S)", [3.70000E+19, 0, 0])
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surface_reaction( "CO(S) + PT(S) => C(S) + O(S)",
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Arrhenius(3.70000E+19, 0, 236500,
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coverage = ['CO(S)', 0.0, 0.0, -33000]))
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# error in paper. This reaction is consistent with the version in the
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# file on the DETCHEM mechanisms web site, but differs from the
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# version in the Applied Catalysis paper.
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surface_reaction( "CO(S) + O(S) => CO2(S) + PT(S)",
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Arrhenius(3.70000E+21, 0, 117600,
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coverage = ['CO(S)', 0.0, 0.0, -33000]))
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# minor diff w paper
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surface_reaction( "CO2(S) + PT(S) => CO(S) + O(S)",
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Arrhenius(3.70000E+19, 0, 173300,
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coverage = ['O(S)', 0.0, 0.0, 94100]))
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surface_reaction( "CO(S) + OH(S) => CO2(S) + H(S)",
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Arrhenius(1.0000E+19, 0, 38700,
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coverage = ['CO(S)', 0.0, 0.0, -30000]))
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surface_reaction( "CO2(S) + H(S) => CO(S) + OH(S)",
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Arrhenius(1.0000E+19, 0, 8400))
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surface_reaction( "CH3(S) + PT(S) => CH2(S) + H(S)",
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Arrhenius(1.2600E+22, 0, 70300))
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surface_reaction( "CH2(S) + H(S) => CH3(S) + PT(S)",
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Arrhenius(3.0900E+22, 0, 0,
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coverage = ['H(S)', 0.0, 0.0, -2800]))
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surface_reaction( "CH2(S) + PT(S) => CH(S) + H(S)",
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Arrhenius(7.3100E+22, 0, 58900,
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coverage = ['C(S)', 0.0, 0.0, 50000]))
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surface_reaction( "CH(S) + H(S) => CH2(S) + PT(S)",
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Arrhenius(3.0900E+22, 0, 0,
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coverage = ['H(S)', 0.0, 0.0, -2800]))
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surface_reaction( "CH(S) + PT(S) => C(S) + H(S)",
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|
Arrhenius(3.0900E+22, 0, 0,
|
|
coverage = ['H(S)', 0.0, 0.0, -2800]))
|
|
|
|
surface_reaction( "C(S) + H(S) => CH(S) + PT(S)",
|
|
Arrhenius(1.2500E+22, 0, 138000))
|
|
|
|
surface_reaction( "H(S) + O(S) => OH(S) + PT(S)",
|
|
Arrhenius(1.2800E+21, 0, 11200))
|
|
|
|
surface_reaction( "OH(S) + PT(S) => H(S) + O(S)",
|
|
Arrhenius(7.39e19, 0, 77300,
|
|
coverage = ['O(S)', 0.0, 0.0, -73200]))
|
|
|
|
surface_reaction( "H2O(S) + PT(S) => H(S) + OH(S)",
|
|
Arrhenius(1.15e19, 0, 101400,
|
|
coverage = ['O(S)', 0.0, 0.0, 167300]))
|
|
|
|
surface_reaction( "2 OH(S) => H2O(S) + O(S)",
|
|
Arrhenius(7.4e20, 0, 74000))
|
|
|
|
surface_reaction( "H2O(S) + O(S) => 2 OH(S)",
|
|
Arrhenius(1.0e20, 0, 43100,
|
|
coverage = ['O(S)', 0.0, 0.0, 240600]))
|
|
|
|
surface_reaction( "H2 + C(S) => CH2(S)",
|
|
stick(0.04, 0, 29700,
|
|
coverage = ['C(S)', 0.0, 0.0, 4600]))
|
|
|
|
surface_reaction( "CH2(S) => C(S) + H2",
|
|
Arrhenius(7.69e13, 0, 25100,
|
|
coverage = ['C(S)', 0.0, 0.0, 50000]))
|
|
|
|
surface_reaction( "H(S) + OH(S) => H2O(S) + PT(S)",
|
|
Arrhenius(2.04e21, 0, 66220))
|
|
|
|
surface_reaction( "CH3(S) + H(S) => CH4 + 2 PT(S)",
|
|
Arrhenius(3.3e21, 0, 50000,
|
|
coverage = ['H(S)', 0.0, 0.0, -2800]))
|
|
|
|
surface_reaction( "CH3(S) + H2O(S) => CH4 + OH(S) + PT(S)",
|
|
Arrhenius(3.7e21, 0, 110600))
|
|
|
|
surface_reaction( "CH3(S) + OH(S) => CH4 + O(S) + PT(S)",
|
|
Arrhenius(3.7e21, 0, 87900))
|