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

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 V ₂O ₅-WO ₃/TiO ₂ (VWT) catalyst and showed nearly an order of magnitude increase in turnover frequency (TOF) value via an H ₂-plasma treatment for selective catalytic reduction of NO with NH ₃. Such oligomeric surface VO _x sites were not only successfully observed and firstly distinguished from WO _x and TiO ₂ 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.