In Situ Fabrication of Ultrasmall Ni Nanoparticles from Ni(OH)2 Precursors for Efficient CO2 Reforming of Methane

Abstract

Metal size is a critical structural parameter for Ni-based catalysts in CO2 reforming of methane. Herein, ultrasmall Ni nanoparticles (3.7 nm) were fabricated from Ni(OH)2 precursors on γ-Al2O3 nanoplates via a simple solution method followed by H2 reduction. The resultant Ni/Al2O3-IS catalyst showed competitive reforming performance. The turnover frequency reached 15.3 s–1 at 700 °C under atmospheric pressure. Methane (CH4) conversion declined marginally from 79.8 to 70.2% after 20 h of reaction. Characterization results reveal that high activity and good stability were endowed by the ultrasmall Ni size and superior coke resistance, respectively. A bifunctional reaction mechanism was identified on the Ni/Al2O3-IS catalyst, wherein the activation of the reactant molecules was facilitated near metal–support interfaces. This work offers a novel strategy to fabricate ultrasmall Ni particles and provides new insights into structure–activity relationships in CO2 reforming of methane.