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To develop customized sulfur–resistant catalysts for the water gas shift (WGS) reaction in the waste–to–hydrogen process, the effects of changing the nucleation conditions of the CeO2 support on catalytic performance were investigated. Supersaturation is a critical kinetic parameter for nuclei formation. The degree of supersaturation of the CeO2 precipitation solution was controlled by varying the cerium precursor concentration from 0.02 to 0.20 M. Next, 2 wt.% of Pt was impregnated on those various CeO2 supports by the incipient wetness impregnation method. The prepared samples were then evaluated in a WGS reaction using waste–derived synthesis gas containing 500 ppm H2S. The Pt catalyst supported by CeO2 prepared at the highest precursor concentration of 0.20 M exhibited the best sulfur resistance and catalytic activity regeneration. The sulfur tolerance of the catalyst demonstrated a close correlation with its oxygen storage capacity and easier reducibility. The formation of oxygen vacancies in CeO2 supports is promoted by the formation of small crystals due to a high degree of supersaturation. [ABSTRACT FROM AUTHOR]

To improve the sulfur tolerance of CeO2-supported Pt catalysts for water gas shift (WGS) using waste-derived synthesis gas, we investigated the effect of synthesis methods on the physicochemical properties of the catalysts. The Pt catalysts using CeO2 as a support were synthesized in various pathways (i.e., incipient wetness impregnation, sol-gel, hydrothermal, and co-precipitation methods). The prepared samples were then evaluated in the WGS reaction with 500 ppm H2S. Among the prepared catalysts, the Pt-based catalyst prepared by incipient wetness impregnation showed the highest catalytic activity and sulfur tolerance due to the standout factors such as a high oxygen-storage capacity and active metal dispersion. The active metal dispersion and oxygen-storage capacity of the catalyst showed a correlation with the catalytic performance and the sulfur tolerance. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Various noble metals (Pt, Rh, Ru, and Pd) were supported on CeO 2 to understand their sulfur-tolerant catalytic activity. The synthesized catalysts were applied to the water-gas shift reaction in the waste-to-hydrogen process with the injection of 500 ppm H 2 S. Among the samples, the PtCe catalyst showed the highest sulfur tolerance and recovery of catalytic activity. Considering the catalytic reaction results and physicochemical properties, the sulfur tolerance of the catalyst is affected by oxygen vacancies and redox properties, which are closely related to the interaction between the metal and the CeO 2 support. In addition, the oxygen storage capacity concentration was used as an indicator for classifying the recovered catalyst and the non-recovered catalyst which had been poisoned by sulfur. [Display omitted] • CeO 2 -based noble metal catalysts are tested for sulfur-injected water gas shift. • Pt-loaded catalyst showed strong sulfur tolerance and regeneration. • Sulfur tolerance is strongly related to oxygen storage capacity of the catalyst. • Regeneration trends are clearly classified based on the oxygen storage capacity. • Certain oxygen vacancy is required for the regeneration of sulfur-poisoned catalyst. [ABSTRACT FROM AUTHOR]

An abstract of the article "The effects of combined training on TUG test, bloodlipids, HOMA-IR and NO in elderly with hypertension" by Kim Eun-Hee and colleagues is presented.