Non-Noble Metal Intermetallic Compound Catalyst Design for Low-Temperature Dry Reforming of Methane: Electronic Origins of Surface Chemistry to Avoid Unselective H ₂ O Production

Trends in the surface chemistry of non-noble transition metal (TM) intermetallic compounds (IMC) (binary combinations of TM and post-transition and semimetals) toward oxygen and oxygen-containing bonds with respect to constituent element selection, bulk stoichiometry, and electronic properties of the intermetallic compound remain undeveloped. Herein, utilizing the dry reforming of CH4 as a probe reaction, we develop these trends in a computational surface science study of a large suite of non-noble metal IMC. A specific focus was drawn on the production of elevated surface chemistry to drive CH4 and CO2 dissociation and limit hydrogenation of O/OH to avoid unselective H2O formation. Kinetic Monte Carlo simulations were utilized with density functional theory quantum chemical inputs to predict the H2:CO product ratio and predicted that elevated surface reactivity greatly improved selectivity and limited H2 and oxidizer loss as H2O. The degree and strength of bonding within the intermetallic compound and lower electronegativity of constituent elements both correlated with limited H2O formation because of improved O/OH stability and naturally attenuated hydrogenation kinetics.