Nanoconfinement Prevents Nickel Catalyst From Fouling

By confining small particles of nickel in the pores of a zirconium dioxide matrix, researchers in China have developed a long-lasting and active catalyst that resists common routes to fouling and deactivation (Chem. Commun., DOI: 10.1039/c2cc37109j). The study may lead to methods for preparing a variety of robust nanocomposite catalysts that tolerate high temperatures and high humidity. Nickel nanoparticles supported on metal oxides serve as catalysts for various types of hydrogenations and other reactions. The catalytically active and low-cost metal could be used more widely, but it’s prone to high-temperature deactivation via particle fusing (sintering) and carbon deposition (coking). Jinlong Gong and coworkers at Tianjin University devised a surfactant-assisted technique for preparing NiO nanoparticles and a hydrothermal method for reducing and confining the particles in a ZrO₂ matrix. Compared with conventional methods for impregnating metals in oxides, the new method yields smaller particles with four times as much surface area. Furthermore, unlike standard supported nickel catalysts, the new ones resist sintering and coking, as determined from 50 hours of hydrogen production via steam reforming of ethanol. The researchers attribute the catalyst stability to the similarity in size of Ni and ZrO₂ particles, which inhibits sintering, and high oxygen mobility in the matrix, which impedes coking.