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Research is being actively conducted to improve the carbon deposition and sintering resistance of Ni-based catalysts. Among them, the Al2O3-supported Ni catalyst has been broadly studied for the dry reforming reaction due to its high CH4 activity at the beginning of the reaction. However, there is a problem of deactivation due to carbon deposition of Ni/Al2O3 catalyst and sintering of Ni, which is a catalytically active material. Supplementing MgO in Ni/Al2O3 catalyst can result in an improved MgAl2O4 spinel structure and basicity, which can be helpful for the activation of methane and carbon dioxide molecules. In order to confirm the optimal supports’ ratio in Ni/MgO-Al2O3 catalysts, the catalysts were prepared by supporting Ni after controlling the MgO:Al2O3 ratio stepwise, and the prepared catalysts were used for CO2 reforming of CH4 (CDR) using coke oven gas (COG). The catalytic reaction was conducted at 800 °C and at a high gas hourly space velocity (GHSV = 1,500,000 h−1) to screen the catalytic performance. The Ni/MgO-Al2O3 (MgO:Al2O3 = 3:7) catalyst showed the best catalytic performance between prepared catalysts. From this study, the ratio of MgO:Al2O3 was confirmed to affect not only the basicity of the catalyst but also the dispersion of the catalyst and the reducing property of the catalyst surface.

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In the Pt/CeO2 catalyst, we found that the loading amount of Pt affects not only the dispersion of Pt but also the interaction between Pt and CeO2, specifically to the oxygen storage capacity. The interface between Pt and CeO2 has some special properties due to oxygen reverse spillover, which affects the oxygen storage capacity of the catalyst. The loading amount of Pt in the Pt/CeO2 catalyst was varied from 0.1 to 10.0 wt %, and the physicochemical properties were compared. The prepared samples were tested to the water–gas shift reaction in the waste-to-hydrogen process with the existence of 500 ppm of H2S to evaluate the sulfur tolerant catalytic performance. Among the samples, the 2.0% Pt/CeO2 catalyst showed the highest sulfur tolerance. Considering the catalytic reaction result and physicochemical properties, the sulfur tolerant catalytic activity can be mainly related to the oxygen storage capacity. From this result, we have concluded that the loading amount of Pt not only affects the dispersion of Pt0 but also affects the oxygen storage capacity of the catalyst.