Carbon supported PdNi alloy nanoparticles on SiO2 nanocages with enhanced catalytic performance

Abstract

Ni(0) nanoparticles (NPs) are unstable and tend to aggregate in water, which poses a considerable challenge in their catalytic application. To overcome these drawbacks, integrated Ni-noble metal bimetallic NPs with a hollow-structured support are expected to enhance performances in heterogeneous catalysis. Herein, we present a simple approach for facile fabrication of Ni NPs embedded in a carbon layer on raspberry-like SiO₂ hollow nanocages with a hydrophobic surface (SiO₂@C-Ni). Owing to the high affinity between Ni and histine-rich protein, the resultant raspberry-like SiO₂@C-Ni composites exhibit good performance in the adsorption of His-rich protein. Moreover, by the galvanic replacement reaction between Ni and Pd²⁺, hollow structured SiO₂@C-PdNi composites are easily obtained, while endowing the SiO₂@C-PdNi composites with a hydrophilic surface, greatly beneficial for the catalysis reaction in the aqueous phase. More attractively, the synthetic strategy could be extended to the synthesis of other Ni-based bimetallic alloy NPs, such as SiO₂@C-AgNi and SiO₂@C-AuNi composites. This work highlights the superiority of transition metal ion mediated RF chemistry, the sol–gel process and emulsifier-free polymerization in the ingenious design of hollow structured materials embedded with well-dispersed metal alloy NPs.