Impact of Ga, Sr, and Ce on Ni/DSZ95 Catalyst for Methane Partial Oxidation in Hydrogen Production

Abstract

The greenhouse gas CH4 is more potent than CO2, although both these gases are solely responsible for global warming. The efficient catalytic conversion of CH4 into hydrogen-rich syngas, which also demonstrates economic viability, can deplete the concentration of CH4. This study examines the partial oxidation of methane (POM) prepared by the wetness impregnation process using 5% Ni supported over DSZ95 (93.3% ZrO2 + 6.7% Sc2O3) and promoted with 1% Ga (gallium), 1% Sr (strontium), and 1% Ce (cerium). These catalysts are characterized by surface area porosity, X-ray diffraction, FT-Infrared spectroscopy, Raman infrared spectroscopy, temperature programmed reduction, CO2 temperature-programmed techniques, desorption techniques, thermogravimetry, and transmission electron microscopy. The characterization results demonstrate that Ni is appropriate for the POM because of its crystalline structure, improved metal support contact, and increased thermal stability with Sr, Ce, and Ga promoters. The synthesized catalyst 5Ni+1Ga-DSZ95 maintained stability for 240 min on stream during the POM at 700 °C. Adding a 1% Ga promoter and active metal Ni to the DSZ95 improved the CH4 conversion from 70.00% to 75.90% and raised the H2 yield from 69.21% to 74.80%, while maintaining the reactants’ stoichiometric ratio of (CH4:O2 = 2:1). The 5Ni+1Ga-DSZ95 catalyst is superior to the other catalysts, given its rich catalyst surface, strong metal support interaction, high surface area and low amount of carbon deposit. The high H2/CO ratio (>2.6) and H2 yield close to 75% indicate that 5Ni+1Ga-DSZ95 is a potent industrial catalyst for hydrogen-rich syngas production through partial oxidation of methane.