Precise control of Pt encapsulation in zeolite-based catalysts for a stable low-temperature CO oxidation reaction

Metal-zeolite catalysts are vital in chemical and fuel production for their great stability, stereo-selectivity, and atom economy. When metal species keep shrinking their sizes to the subnanometer region, their spatial distribution in the zeolite framework/channels could have a great impact on their catalytic performance. Here, we precisely control the Pt species loaded on a silicalite-1 zeolite and characterize their structural status to the catalytic performance for CO oxidation. We find that Pt species exits as few-atom clusters encapsulated in the channels and destructively embedded Pt nanoparticles in the framework, besides the conventional surface-supported Pt. By utilizing effective Pt sites and limiting their sizes in the zeolite, we can maximize the catalytic CO oxidation performance of 1 at.% Pt-loaded zeolite catalysts to achieve a T-100 as low as 90 degrees C and a stable reaction above 216 h.