Rationally Engineering a CuO/Pd@SiO 2 Core-Shell Catalyst with Isolated Bifunctional Pd and Cu Active Sites for n -Butylamine Controllable Decomposition.

Volatile organic amines are a category of typical volatile organic compounds (VOCs) extensively presented in industrial exhausts causing serious harm to the atmospheric environment and human health. Monometallic Pd and Cu-based catalysts are commonly adopted for catalytic destruction of hazardous organic amines, but their applications are greatly limited by the inevitable production of toxic amide and NO x byproducts and inferior low-temperature activity. Here, a CuO/Pd@SiO 2 core-shell-structured catalyst with diverse functionalized active sites was creatively developed, which realized the total decomposition of n -butylamine at 260 °C with a CO 2 yield and N 2 selectivity reaching up to 100% and 98.3%, respectively (obviously better than those of Pd@SiO 2 and CuO/SiO 2 ), owing to the synergy of isolated Pd and Cu sites in independent mineralization of n -butylamine and generation of N 2 , respectively. The formation of amide and short-chain aliphatic hydrocarbon intermediates via C-C bond cleavage tended to occur over Pd sites, while the C-N bond was prone to breakage over Cu sites, generating NH 2 · species and long free-N chain intermediates at low temperatures, avoiding the production of hazardous amide and NO x . The SiO 2 channel collapse and H + site production resulted in the formation of N 2 O via suppressing NH 2 · diffusion. This work provides critical guidance for a rational fabrication of catalysts with high activity and N 2 selectivity for environmentally friendly destruction of nitrogen-containing VOCs.