Methanation of Carbon Dioxide on Ni(100) and the Effects of Surface Modifiers?
نویسندگان
چکیده
The methanation of COz over Ni(100) was studied with H2/C02 ratios of 4/1 and 96/1 (total pressures of 120 and 97 torr) for temperatures between 450 and 750 K. Large amounta of CO were formed, with activation energies of 21.2 and 17.4-19.7 kcal mol-' for CH4 and CO formation, respectively. The absolute CHI production rates were very close to those seen for methanation of CO. These results support a mechanism with CO and C(a) intermediates. Adsorption of K and/or S resulted in changes in the amounta and rates of CHI and CO production, but no change in activation energy. Results showed that the effects of K(a) can compensate for the effects of S(a), and support electronic interaction as responsible for poisoning/promotion effects.
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