Hexagonal boron nitride heterostructure to control the oxidation states and SO2 resistance of the V2O5-WO3/TiO2 catalyst for the NH3-SCR reaction across a wide temperature range

Abstract

The development and commercialization of efficient NH3-selective catalytic reduction catalysts with a broad operational temperature range are crucial for mitigating NOx emissions from stationary sources; however, these remain a significant challenge. This study describes a strategy to extend the operational temperature window of commercially viable V-based catalysts through nanoscale heterostructure formation by hexagonal boron nitride (h-BN) incorporation, which promotes the formation of V4+ and W4+ species in V and W oxide nanoparticles, enhancing the low-temperature catalytic activity of the system. Additionally, in-situ DRIFT results reveal that the presence of h-BN suppresses the formation of sulfate on the catalyst surface. Among the synthesized catalysts, the system with 10 % h-BN incorporation shows the highest V4+ ratio of 67.0 % with an NO conversion of 93.6 % at 240 degrees C under a flow rate of 500 mL & sdot;min- 1. Furthermore, monolithic catalysts containing only 1 wt% of V show excellent catalytic performance (90.0 % NO conversion at 240 degrees C under a high flow rate of 20 L & sdot;min- 1, corresponding to a high throughput of 2.14 x 10-6 molNO center dot s- 1) along with excellent resistance to poisoning, including exposure to 300 ppm of SO2 and 10 % H2O, thereby exhibiting high potential practical applicability in industrial NOx abatement. The results are expected to expedite research on the design and development of highperformance catalysts supporting global efforts to mitigate environmental pollution and related challenges.