13C and 14C kinetic isotope effects in the reduction of CO over an Mg surface

Abstract

¹³ C and ¹⁴C kinetic isotope effects in the reaction CO + Mg → C + MgO have been determined experimentally in the temperature range 723–823 K. The values obtained are temperature independent within experimental error and amount to 1.017 ± 0.001 and 1.035 ± 0.002 for ¹³C and ¹⁴C, respectively. In the theoretical interpretation of the results, based on Bigeleisen's formalism, C—O [graphic omitted] and C—O—Mg were considered as transition states of the rate-determining and isotope-fractionation governing step of the reaction mechanism. The former was found to be acceptable.