Freestanding Cobalt-Aluminum Oxides on USY Zeolite as an Efficient Catalyst for Selective Catalytic Reduction of NO_x

The selective catalytic reduction of NO_x with propane as reductant (C₃H₈-SCR) is an attractive alternative for the depletion of NO_x generated under lean burn condition. Herein, we developed a novel and low-cost three-dimensional CoO_x@USY catalyst applied for catalytic reduction of NO with propane for the first time. The as-fabricated hierarchical architecture was beneficial for exposing the active sites maximally, enhancing mass transports as well as integrating strongly interacted cobalt-aluminum oxide together with the nature of USY zeolite. Serving as a SCR catalyst, the designed CoO_x@USY yielded a remarkably elevated NO conversion efficiency due to the synergy between the Co−Al oxide shell and the USY zeolite core, showing promising application for the pollution abatement of nitric oxides. The reaction mechanism was also studied in detail trough the in situ DRIFTS technique. This work would provide new insights into the design and synthesis of transition metal-based catalysts with a high-efficiency for reducing NO emission.