Microfabrication Enables Quantification of Interfacial Activity in Thermal Catalysis

A myriad of heterogeneous catalysts comprises multiple phases that need to be precisely structured to exert their maximal contribution to performance through electronic and structural interactions at their peripheries. In view of the nanometric, tridimensional, and anisotropic nature of these materials, a quantification of the interface and the impact of catalytic sites located there on the global performance is a highly challenging task. Consequently, the true origin of catalysis often remains subject of debate even for widely studied materials. Herein, an integrated strategy based on microfabricated catalysts and a custom-designed reactor is introduced for determining interfacial contributions upon catalytic activity assessment under process-relevant conditions, which can be easily implemented in the common catalysis research infrastructure and will accelerate the rational design of multicomponent heterogeneous catalysts for diverse applications. The method is validated by studying the high-pressure continuous-flow hydrogenation of CO and CO₂ over Cu-ZnO catalysts, revealing linear correlations between the methanol formation rate and the interface between the metal and the oxide. Characterization of fresh and used materials points to the model catalyst preparation as the current challenge of the methodology that can be addressed through further development of nanotechnological tools.