Supported Ni catalyst on a natural halloysite derived silica–alumina composite oxide with unexpected coke-resistant stability for steam-CO2 dual reforming of methane

Abstract

The natural halloysite derived silica–alumina composite oxides (SA–H) through calcination at diverse temperatures were employed as supports for synthesizing novel supported Ni catalysts towards steam-CO₂ dual reforming of methane (SCRM) for the production of synthesis gas. The effect of calcination temperature on the nature of the as-prepared supports and the supported Ni catalysts was investigated by using various characterization techniques including transmission electron microscopy (TEM), N₂ adsorption–desorption (BET), X-ray diffraction (XRD), CO chemisorption, thermogravimetric analysis (TGA), and H₂ temperature-programmed reduction (H₂-TPR). The supported Ni catalyst on the halloysite derived silica–alumina nanorod (Ni/SANR–H) prepared by calcination at 1000 °C exhibited higher catalytic activity with similar selectivity in comparison with the ones prepared with the other temperatures, ascribed to higher Ni dispersity. More interestingly, the robust Ni/SANR–H catalyst exhibited unexpectedly catalytic stability for a SCRM reaction with much higher coke and Ni-sintering resistance than the supported Ni catalyst on traditional silica alumina prepared by a precipitation method (Ni/SA-P). The unexpected coke-resistant capacity of the Ni/SANR–H catalyst endows it to be a promising candidate for synthesis gas production through a SCRM reaction.