Adsorption and reaction co-induced bifunctional catalytic removal of NOx and toluene over a reaction site-isolation catalyst.

Nitrogen oxides (NOx) and volatile organic compounds (VOCs) released from industrial sources react to generate pollutants such as O3 through photochemical reactions. In order to realize the simultaneous removal of NOx and VOCs, this work provides a reaction site-isolation (RSI) catalyst with isolated reaction zones of toluene oxidation over Cu-Ce sites and NH3-SCR over V-W sites, respectively. Reaction site-isolation significantly weakens the impact of competitive adsorption between different reactants and reduces the formation of by-products during the reaction. The NO and toluene conversion both reached to 100 % at 275 ℃ and the catalyst demonstrated great sulfur resistance and stability. Characterization of the catalyst revealed that the interaction between Cu and Ce promoted the formation of oxygen vacancies, while the introduction of Cu increased the adsorption sites of toluene. Notably, DFT calculation and activation energy calculation reveal that the adsorption performance of active sites for reactant and the reaction activation energy required for reactions are different. Therefore, this work achieves adsorption and reaction co-induced bifunctional catalysis by isolating active sites.