SURFACE MECHANISM OF POX of CH4 on PT wire gauze **** *********************************************************************** **** * **** CH4-O2 SURFACE MECHANISM ON PT * **** * **** Version 1.0 Spring 2005 * **** * **** Raul Quiceno, Olaf Deutschmann, IWR, Heidelberg University, * **** Germany * * **** Contact: mail@detchem.com (O. Deutschmann) * **** * **** Reference: * **** R. Quiceno, J. Perez-Ramyrez, J. Warnatz, O. Deutschmann. * **** Appl. Catal. A: General (2006) * **** www.detchem.com/mechanisms * **** * **** * **** Kinetic data format: DETCHEM * **** k = A * T**b * exp (-Ea/RT) A b Ea * **** (cm,mol,s) - kJ/mol * **** * **** STICK: A in next reaction is initial sticking coefficient * **** * **** $.. : additional coverage dependence of Ea (3rd column) * **** or changed reaction order (2nd column) * **** * **** see manuals on www.detchem.com for details * **** * **** The kinetic data of the backward reactions of * **** reactions in Section 3 are calculated * **** from thermodynamics (k_b = k_f /K) * **** * **** Surface site density: 2.72E-9 mol/cm**2 * **** * **** DETCHEM format * **** * *********************************************************************** ********************************************************************* **** 1. ADSORPTION ********************************************************************* STICK H2 +_Pt_ +_Pt_ >H_Pt +H_Pt 0.046E-00 0.0 0.0 $_Pt_ 0.0 -1.0 0.0 O2 +_Pt_ +_Pt_ >O_Pt +O_Pt 1.891E+21 -0.5 0.0 STICK CH4 +_Pt_ +_Pt_ >CH3_Pt +H_Pt 9.000E-04 0.0 72.0 CH4 +O_Pt +_Pt_ >CH3_Pt +OH_Pt 5.000E+18 0.7 42.0 $O_Pt 0.0 0.0 -8.0 STICK CH4 +OH_Pt +_Pt_ >CH3_Pt +H2O_Pt 1.000E-00 0.0 10.0 STICK H2O +_Pt_ >H2O_Pt 7.500E-01 0.0 0.0 STICK CO2 +_Pt_ >CO2_Pt 5.000E-03 0.0 0.0 STICK CO +_Pt_ >CO_Pt 8.400E-01 0.0 0.0 ********************************************************************* **** 2. DESORPTION ********************************************************************* H_Pt +H_Pt >_Pt_ +_Pt_ +H2 3.700E+21 0.0 67.4 $H_Pt 0.0 0.0 10.0 O_Pt +O_Pt >_Pt_ +_Pt_ +O2 3.700E+21 0.0 235.5 $O_Pt 0.0 0.0 188.28 H2O_Pt >H2O +_Pt_ 4.500E+12 0.0 41.8 CO_Pt >CO +_Pt_ 1.000E+15 0.0 146.0 $CO_Pt 0.0 0.0 33.0 CO2_Pt >CO2 +_Pt_ 1.000E+13 0.0 27.07 ********************************************************************* **** 3. SURFACE REACTIONS ********************************************************************* C_Pt +O_Pt >CO_Pt +_Pt_ 3.700E+19 0.0 0.0 CO_Pt +_Pt_ >C_Pt +O_Pt 3.700E+19 0.0 236.5 $CO_Pt 0.0 0.0 33.0 CO_Pt +O_Pt >CO2_Pt +_Pt_ 3.700E+21 0.0 117.6 $CO_Pt 0.0 0.0 33.0 CO2_Pt +_Pt_ >CO_Pt +O_Pt 3.700E+19 0.0 173.3 $O_Pt 0.0 0.0 -94.14 CO_Pt +OH_Pt >CO2_Pt +H_Pt 1.000E+19 0.0 38.7 $CO_Pt 0.0 0.0 30.0 CO2_Pt +H_Pt >CO_Pt +OH_Pt 1.000E+19 0.0 8.4 CH3_Pt +_Pt_ >CH2_Pt +H_Pt 1.262E+22 0.0 70.3 CH2_Pt +H_Pt >CH3_Pt +_Pt_ 3.090E+22 0.0 0.0 $H_Pt 0.0 0.0 2.8 CH2_Pt +_Pt_ >CH_Pt +H_Pt 7.314E+22 0.0 58.9 $C_Pt 0.0 0.0 -50.0 CH_Pt +H_Pt >CH2_Pt +_Pt_ 3.090E+22 0.0 0.0 $H_Pt 0.0 0.0 2.8 CH_Pt +_Pt_ >C_Pt +H_Pt 3.090E+22 0.0 0.0 $H_Pt 0.0 0.0 2.8 C_Pt +H_Pt >CH_Pt +_Pt_ 1.248E+22 0.0 138.0 H_Pt +O_Pt >OH_Pt +_Pt_ 1.280E+21 0.0 11.2 OH_Pt +_Pt_ >H_Pt +O_Pt 7.390E+19 0.0 77.30 $O_Pt 0.0 0.0 73.22 H2O_Pt +_Pt_ >H_Pt +OH_Pt 1.150E+19 0.0 101.4 $O_Pt 0.0 0.0 -167.36 OH_Pt +OH_Pt >H2O_Pt +O_Pt 7.400E+20 0.0 74.0 H2O_Pt +O_Pt >OH_Pt +OH_Pt 1.000E+20 0.0 43.1 $O_Pt 0.0 0.0 -240.58 ********************************************************************* **** 4. STEPS ADDED from C2H6/O2/Pt Zerkle et al., J. Catal. (2000) ********************************************************************* STICK H2 +C_Pt >CH2_Pt 4.000E-02 0.0 29.7 $C_Pt 0.0 0.0 -4.6 CH2_Pt >C_Pt +H2 7.690E+13 0.0 25.1 $C_Pt 0.0 0.0 -50.0 H_Pt +OH_Pt >H2O_Pt +_Pt_ 2.040E+21 0.0 66.22 CH3_Pt +H_Pt >CH4 +_Pt_ +_Pt_ 3.300E+21 0.0 50.0 $H_Pt 0.0 0.0 2.8 CH3_Pt +H2O_Pt >CH4 +OH_Pt +_Pt_ 3.700E+21 0.0 110.6 CH3_Pt +OH_Pt >CH4 +O_Pt +_Pt_ 3.700E+21 0.0 87.9 ********************************************************************* END