Cost-Effective Single-Step Synthesis of Metal Oxide-Supported Ni Catalyst for H2-Production Through Dry Reforming of Methane.

Preparing catalysts from cheap metal precursors in a single pot are an appealing method for reducing catalytic preparation costs, minimizing chemical waste, and saving time. With regards to the catalytic conversion of dry reforming of methane, it offers the prospect of significantly reducing the cost of H₂ production. Herein, NiO-stabilized metal oxides like Ni/TiO₂, Ni/MgO, Ni/ZrO₂, and Ni/Al₂O₃ are prepared at two different calcination temperatures (600 °C and 800 °C). Catalysts are characterized by X-ray diffraction, Raman spectroscopy, surface area-porosity analysis, Temperature program experiments, infrared spectroscopy, and thermogravimetry analysis. The MgO-supported Ni catalyst (Ni/MgO-600), ZrO₂-supported Ni catalyst (Ni/ZrO₂-600), and Al₂O₃-supported Ni (Ni/Al₂O₃-600) catalyst calcined at 600 °C show initial equal H₂ yields (~ 55%). The population of CH₄ decomposition sites over ZrO₂-supported Ni catalyst remains highest, but H₂-yield drops to 45% against high coke deposition. The catalytic activity remains constant over the Ni/MgO-600 catalyst due to the enrichment of "surface interacted CO₂-species". MgO-supported Ni catalyst calcined at 800 °C undergoes weak interactions of NiO-M′ (M′ = support), serious loss of CH₄ decomposition sites and potential consumption of H₂ by reverse water gas shift reaction, resulting in inferior H₂ yield. H₂-yield remains unaffected over an Al₂O₃-supported Ni catalyst even against the highest coke deposition due to the formation of stable Ni (which exsolves from NiAl₂O₄) and proper matching between carbon formation and rate of carbon diffusion. [ABSTRACT FROM AUTHOR]