Material characterization of Au/Ni nanocatalyst for low-temperature carbon dioxide methanation

Abstract

The nanocatalyst for the carbon oxide methanation process is used, among others, in environmental protection, chemical industry, and renewable energy sources. The use of a suitable catalyst allows a chemical reaction to be carried out between unreacted gaseous substrates. The most frequently studied monometallic catalysts are: Ni, Ru, Rh, Pt, Au, Cu, Fe. Bimetallic nanocatalysts are equally popular. Their catalytic properties differ from those of pure component metals. Numerous studies indicate a positive effect in catalysts containing particles: Au-Ag, Au-Pt, Au-Pd, Pd-Ni, Pd-Cu. A review of the literature indicates that examples of the use of metal nanoparticles of spherical shape deposited on a nickel substrate in the methanation process are known, but so far no attempt has been shown in publications to produce a catalyst based on gold nanoparticles with developed surface in the form of spiky (nanourchins, nanostars) on a nickel base as presented in the article. Gold nanourchins are deposited on a nickel substrate in the form of a nickel molecular mesh. The prepared nanocatalyst has been subjected to structural analysis using a transmission electron microscope (TEM). Scanning Electron Microscopic (SEM) images were taken with a Zeiss Supra 35. Qualitative studies of chemical composition were also performed using the Energy Dispersive Spectrometer (EDS). Based on the TEM results, the appearance of the X-ray diffraction pattern was computer modelled. A nanocatalyst was obtained with a high coverage of the nickel molecular mesh surface with gold nanoparticles not exceeding 50 nm in diameter.