Support-Boosted Nickel Phosphide Nanoalloy Catalysis in the Selective Hydrogenation of Maltose to Maltitol
Sho Yamaguchi, Shu Fujita, Kiyotaka Nakajima, Seiji Yamazoe, Jun Yamasaki, Tomoo Mizugaki, Takato Mitsudome
Abstract
Metal phosphide catalysts have attracted attention for organic synthesis owing to their stability and high activity. Nevertheless, metal–support interactions and support-boosted metal phosphide catalysis remain unexplored. Herein, we report the development of a hydrotalcite (HT: Mg6Al2CO3(OH)16·4(H2O))-supported nickel phosphide nanoalloy (nano-Ni2P/HT) that exhibits high activity for the hydrogenation of maltose, which is an important reaction for producing maltitol as a sweetener and food additive. The HT support drastically increased the catalytic activity of nano-Ni2P, allowing nano-Ni2P/HT to outperform conventional catalysts. Various spectroscopic studies revealed that cooperative catalysis by nano-Ni2P and HT plays a key role in the efficient hydrogenation of maltose. The cooperative catalysis enabled high-yield production of maltitol, even at ambient temperature. Furthermore, nano-Ni2P/HT was successfully recovered and reused while retaining its high activity and selectivity. Notably, nano-Ni2P/HT operated well in concentrated maltose solutions (>50 wt %), demonstrating that the high performance of this catalyst will pave the way for the efficient and sustainable production of maltitol.