Dehydrogenation and dehydration of formic acid over orthorhombic molybdenum carbide.

The dehydrogenation and dehydration of formic acid is investigated on the -MoC (100) catalyst surface using time independent density functional theory. The energetics of the two mechanisms are calculated, and the thermochemistry and kinetics are discussed using the transition state theory. Subsequently, microkinetic modelling of the system is conducted, considering the batch reactor model. The potential energy landscape of the reaction shows a thermodynamically favourable cleavage of H-COOH to form CO; however, the kinetics show that the dehydrogenation mechanism is faster and CO is continuously formed. The effect of HCOOH adsorption on the surface is also analysed, in a temperature-programmed desorption, with the conversion proceeding at under 350 K and desorption of CO is observed with a selectivity of about 100 %, in line with the experimental reports.