Highly active and stable heterogeneous catalysts based on the entrapment of noble metal nanoparticles in 3D ordered porous carbon

Heterogeneous catalysts that are prepared by immobilizing noble metal nanoparticles (NPs) on solid matrices can serve as efficient catalysts in various catalytic reactions. However, the immobilized NPs usually suffer from detachment or migration during the catalytic process owing to their weak interactions with the matrices. Here, we developed a facile approach for the synthesis of high active and stable heterogeneous catalysts by entrapping Pd and Ru NPs in 3D ordered hierarchically porous inverse opal carbon (IOC). For these catalysts, the 3D open-porous structure on multiple length scales provides the reactants easy access to the catalytically active NPs while the entrapment of NPs inside IOC ensures their high dispersion and stability during the catalysis. As a result, the as-prepared catalysts exhibited both high activity and stability for the oxidation of CO and electrocatalysis of VO2+/VO2+ redox couples. The conversion rate of CO over the IOC-PdNPs catalyst reached >98% at 200 °C, which showed no decrease after reacting for 10 h. The IOC-RuNPs-based working electrode exhibited highly reversible redox potentials at 1.25 V and 0.78 V, respectively, and no change of peak currents and peak potential separation were observed for 200 cycles of cyclic voltammetry (CV) measurements.