Plasma-assisted manipulation of vanadia nanoclusters for efficient selective catalytic reduction of NO_x

Supported nanoclusters (SNCs) with distinct geometric and electronic structures have garnered significant attention in the field of heterogeneous catalysis. However, their directed synthesis remains a challenge due to limited efficient approaches. This study presents a plasma-assisted treatment strategy to achieve supported metal oxide nanoclusters from a rapid transformation of monomeric dispersed metal oxides. As a case study, oligomeric vanadia-dominated surface sites were derived from the classic supported V₂O₅-WO₃/TiO₂ (VWT) catalyst and showed nearly an order of magnitude increase in turnover frequency (TOF) value via an H₂-plasma treatment for selective catalytic reduction of NO with NH₃. Such oligomeric surface VO_x sites were not only successfully observed and firstly distinguished from WO_x and TiO₂ by advanced electron microscopy, but also facilitated the generation of surface amide and nitrates intermediates that enable barrier-less steps in the SCR reaction as observed by modulation excitation spectroscopy technologies and predicted DFT calculations.