Surface design of V2O5–CeO2–TiO2/SiC catalytic membrane for high-efficiency synergistic removal of NO and dust

For catalytic membranes, the loading of catalysts provides the membrane substrate with novel catalytic functionality, while simultaneously inducing membrane surface reconstruction. However, the effect of such surface reconstruction on performance remains unclear. Herein, VCeTi/SiC catalytic membranes with distinct surface structures were fabricated by three distinct preparation routes. Their NH 3 -SCR activity, gas permeance, and separation performance were systematically evaluated. For both VCeTi/SiC-A and VCeTi/SiC–B, the multi-step impregnation and catalyst blockage led to significantly reduced pore sizes (7.6 μm and 5.4 μm) and poor pore size distributions. In contrast, the VCeTi/SiC–C catalytic membrane prepared by single-step solution impregnation method exhibited an optimal catalyst distribution while largely maintaining a concentrated pore size distribution almost identical to the original catalytic membrane. Benefiting from the more uniform gas flow within the carrier owing to its concentrated pore size distribution, it exhibited the widest operating temperature window for NH 3 -SCR with >90% NO conversion from 300 to 450 °C. Meanwhile, VCeTi/SiC–C also displayed the improved pore size (8.0 μm), the highest gas permeance (380 m 3  m −2  h −1 ·kPa −1 ) and the lowest filtration resistance. Furthermore, we discovered "defect-compensating effect" of dust in combined removal experiment, where dust particulates contribute to enhanced denitration performance. This work provides critical insights into the surface design of high-performance catalytic membranes for medium-high temperature gas purification applications.