Activity and stability descriptors of Ni based alloy catalysts for dry reforming of methane: A density functional theory study

Experimentally determined catalytic activity and stability of alumina supported Ni and Ni 3 M (M = Fe, Co, Cu) alloy catalysts for the dry reforming of methane (DRM) were rationalized by density functional theory (DFT) studies. Ni 3 M slab models were prepared based on the experimental characterization data and DFT calculated segregation energies. First dehydrogenation step of CH 4 which is the rate determining step in DRM was modeled on the Ni(111) and Ni 3 M(111) surfaces. Calculated reaction energetics show that Brønsted–Evans–Polanyi relationship holds true for this catalytic reaction system. A linear correlation was found between turnover frequency values of CH 4 and the calculated dissociation energy of CH 4 . Interestingly, a linear correlation was found between percentage deactivation of catalysts and the calculated carbon adsorption energy. Based on these correlations, we propose that the dissociation energy of CH 4 is a suitable activity descriptor and the adsorption energy of carbon is a suitable stability descriptor for these Ni and Ni 3 M alloy catalysts.