SURFACE MECHANISM OF CH4 REFORMING AND OXIDATION OVER NI *********************************************************************** **** * **** CH4 ON Ni - SURFACE MECHANISM * **** * **** Version 1.0 January 21, 2005 * **** * **** L. Maier, O. Deutschmann * **** University of Karlsruhe, Germany * **** Contact: mail@detchem.com (O. Deutschmann) * **** * **** * **** NOTE: That is a first version that needs further * **** improvements, * **** e.g. NiO formation, coking, * **** temp. range around 800C now * **** * **** * **** Ref: E. Hecht, G.K. Gupta, H. Zhu. A.M. Dean, R.J. Kee, * **** L. Maier, O. Deutschmann. * **** Applied Catalysis A: General 295 (2005) 40–51 * **** * **** 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 are calculated * **** from thermodynamics (k_b = k_f /K) at 800 C * **** * **** Surface site density: 2.60E-9 mol/cm**2 * **** * **** DETCHEM format * **** * *********************************************************************** *********************************************************************** **** 1. ADSORPTION / DESORPTION *********************************************************************** STICK H2 +_Ni_ +_Ni_ >H_Ni +H_Ni 1.000E-02 0.0 0.00 **** H_Ni +H_Ni >_Ni_ +_Ni_ +H2 5.593E+19 0.0 88.12 **** STICK O2 +_Ni_ +_Ni_ >O_Ni +O_Ni 1.000E-02 0.0 0.00 **** O_Ni +O_Ni >_Ni_ +_Ni_ +O2 2.508E+23 0.0 470.39 **** STICK CH4 +_Ni_ >CH4_Ni 8.000E-03 0.0 0.00 **** CH4_Ni >_Ni_ +CH4 5.302E+15 0.0 33.15 **** STICK H2O +_Ni_ >H2O_Ni 1.000E-01 0.0 0.00 **** H2O_Ni >_Ni_ +H2O 4.579E+12 0.0 62.68 **** STICK CO2 +_Ni_ >CO2_Ni 1.000E-05 0.0 0.00 **** CO2_Ni >_Ni_ +CO2 9.334E+07 0.0 28.80 **** STICK CO +_Ni_ >CO_Ni 5.000E-01 0.0 0.00 **** CO_Ni >_Ni_ +CO 4.041E+11 0.0 112.85 $CO_Ni 0.0 50.00 *********************************************************************** **** 2. SURFACE REACTIONS *********************************************************************** O_Ni +H_Ni >OH_Ni +_Ni_ 5.000E+22 0.0 97.90 **** OH_Ni +_Ni_ >O_Ni +H_Ni 2.005E+21 0.0 37.19 **** OH_Ni +H_Ni >H2O_Ni +_Ni_ 3.000E+20 0.0 42.70 **** H2O_Ni +_Ni_ >OH_Ni +H_Ni 2.175E+21 0.0 91.36 **** OH_Ni +OH_Ni >O_Ni +H2O_Ni 3.000E+21 0.0 100.00 **** O_Ni +H2O_Ni >OH_Ni +OH_Ni 5.423E+23 0.0 209.37 **** O_Ni +C_Ni >CO_Ni +_Ni_ 5.200E+23 0.0 148.10 **** CO_Ni +_Ni_ >O_Ni +C_Ni 1.418E+22 -3.0 115.97 $CO_Ni 0.0 50.00 **** O_Ni +CO_Ni >CO2_Ni +_Ni_ 2.000E+19 0.0 123.60 $CO_Ni 0.0 50.00 **** CO2_Ni +_Ni_ >O_Ni +CO_Ni 3.214E+23 -1.0 86.50 **** HCO_Ni +_Ni_ >CO_Ni +H_Ni 3.700E+21 0.0 0.00 $CO_Ni 0.0 -50.00 **** CO_Ni +H_Ni >HCO_Ni +_Ni_ 2.338E+20 -1.0 127.98 **** HCO_Ni +_Ni_ >O_Ni +CH_Ni 3.700E+24 -3.0 95.80 **** O_Ni +CH_Ni >HCO_Ni +_Ni_ 7.914E+20 0.0 114.22 **** CH4_Ni +_Ni_ >CH3_Ni +H_Ni 3.700E+21 0.0 57.70 **** CH3_Ni +H_Ni >CH4_Ni +_Ni_ 4.438E+21 0.0 58.83 **** CH3_Ni +_Ni_ >CH2_Ni +H_Ni 3.700E+24 0.0 100.00 **** CH2_Ni +H_Ni >CH3_Ni +_Ni_ 9.513E+22 0.0 52.58 **** CH2_Ni +_Ni_ >CH_Ni +H_Ni 3.700E+24 0.0 97.10 **** CH_Ni +H_Ni >CH2_Ni +_Ni_ 3.008E+24 0.0 76.43 **** CH_Ni +_Ni_ >C_Ni +H_Ni 3.700E+21 0.0 18.80 **** C_Ni +H_Ni >CH_Ni +_Ni_ 4.400E+22 0.0 160.49 **** O_Ni +CH4_Ni >CH3_Ni +OH_Ni 1.700E+24 0.0 88.30 **** CH3_Ni +OH_Ni >O_Ni +CH4_Ni 8.178E+22 0.0 28.72 **** O_Ni +CH3_Ni >CH2_Ni +OH_Ni 3.700E+24 0.0 130.10 **** CH2_Ni +OH_Ni >O_Ni +CH3_Ni 3.815E+21 0.0 21.97 **** O_Ni +CH2_Ni >CH_Ni +OH_Ni 3.700E+24 0.0 126.80 **** CH_Ni +OH_Ni >O_Ni +CH2_Ni 1.206E+23 0.0 45.42 **** O_Ni +CH_Ni >C_Ni +OH_Ni 3.700E+21 0.0 48.10 **** C_Ni +OH_Ni >O_Ni +CH_Ni 1.764E+21 0.0 129.08 **** END