Heterogeneous sintering and surficial etching strategy for high-performance Cu₂CoO₄-SiC catalytic membranes in simultaneous multipollutant removal

SiC catalytic membranes with superior mechanical and multipollutant removal performance are highly sought after for industrial emission control applications. However, achieving this synergy through sintering processes is challenging due to the temperature difference between the catalysts and the membrane, along with the formation of inactive silicates, both of which result in the deactivation of the catalytic membrane. Herein, a heterogeneous sintering mechanism was introduced to fabricate a Cu₂CoO₄-SiC catalytic membrane with both these prominent performance using liquid-phase sintering of CuO and reaction sintering of Co₃O₄, assisted by a surficial etching process for in-situ construction of active metal oxides. The Cu₂CoO₄-SiC catalytic membrane displays exceptional bending strength and gas permeance of 15.2 MPa and 649.52 m³·m⁻²·h⁻¹·kPa⁻¹, respectively, along with a 99.99 % filtration efficiency and a 100 % toluene oxidation efficiency. The enhanced bending strength is due to the early onset of reactive sintering process promoted by liquid-phase sintering process, as well as the prevention of CuCo₂O₄ compound generation. The high gas permeance is facilitated by the continuous separation layer sintered at a lower temperature, based on a pore-sealing strategy. Furthermore, the improved toluene oxidation performance is ascribed to the reinforced electron transfer and oxygen adsorption capacity on the CuO-Co₃O₄ composite nanoparticles within the Cu₂CoO₄-SiC catalytic membrane. This dual synergistic enhancement strategy offers significant potential for developing other high-performance ceramic catalytic membranes for multipollutant control.