CO2 hydrogenation over heterogeneous catalysts at atmospheric pressure: from electronic properties to product selectivity

Abstract

The production of chemicals and fuels via chemical reduction of CO₂ by green H₂ represents a promising means of mitigating CO₂ emissions. The heterogeneous catalytic reaction of CO₂ and H₂ under atmospheric pressure primarily produces CO and CH₄, while CH₃OH and C₂₊ hydrocarbons are obtained at high pressure. Improving the catalytic selectivity improves the energy efficiency for a given yield and greatly reduces the downstream separation costs. In this work, we review the recent progress in tuning the selectivity of CO₂ hydrogenation over heterogeneous catalysts at atmospheric pressure. We describe fundamental insights into the relationships among the electronic properties of active metals, the binding strengths of key intermediates, and the CO₂ hydrogenation selectivity. The manipulation of the electronic properties, and consequently the product selectivity, can be achieved mainly by controlling the particle size, bimetallic effects, and strong metal–support interactions. Finally, we discuss challenges and opportunities for the rational design of CO₂ hydrogenation catalysts with high activity and desired selectivity.