Ni Nanoparticles Grown on SiO2 Supports Using a Carbon Interlayer Sacrificial Strategy for Chemoselective Hydrogenation of Nitrobenzene and m-Cresol

To efficiently increase the dispersity of metal nanoparticles (NPs) of the supported-type catalyst is crucial for promoting their catalytic performance owing to the enlarged amount of exposed active sites and the strengthened metal-support interaction. Therefore, to develop a facile and practical method for preparing a supported-type catalyst with high dispersity is of great significance, but remains a challenge. In this work, inspired by the previously reported non-noble metal sacrificial approach, we report a facile and practical carbon interlayer sacrificial (CIS) strategy for preparing supported Ni NP catalysts on silica rod (10%Ni/r-SiO2-CIS) with high dispersity. This strategy involves two steps: one is depositing carbon on silica rod (r-SiO2) to form the corresponding carbon-coated silica (r-SiO2 gC) carrier through a hydrothermal process in the presence of glucose; the other is loading metal precursor on r-SiO2 gC through an incipient wetness impregnation (IWI) process followed by hydrogenation for carbon elimination. The method has been extended to the preparation of supported Ni NPs on the silica sphere (10%Ni/s-SiO2-CIS) with high Ni dispersity by using the silica sphere (s- SiO2) as the carrier. For comparison, the conventional-supported Ni NP catalysts (10%Ni/r-SiO2 and 10%Ni/s-SiO2) were also prepared by using a similar method to that for 10%Ni/r-SiO2-CIS and 10%Ni/s-SiO2-CIS except for absence of the carbon-coating process. Owing to the more exposed active sites and the strengthened metal-support resulting from the higher Ni dispersity, both 10%Ni/r-SiO2-CIS and 10%Ni/s-SiO2-CIS catalysts show much superior catalytic properties for the chemoselective hydrogenation of nitrobenzene and m-cresol to their corresponding 10%Ni/r-SiO2 and 10%Ni/s-SiO2. This work opens up an avenue for designing and preparing other outstanding supported metal NP catalysts with high metal dispersity for diverse catalytic transformations.

Automated summary

Efficiently increasing the dispersity of metal nanoparticles on supported catalysts is crucial for enhancing catalytic performance. In this work, a carbon interlayer sacrificial strategy was developed to prepare supported Ni NP catalysts with high dispersity, leading to superior catalytic properties for chemoselective hydrogenation reactions.