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Citric acid, one of the representative chelate compounds, has been widely used as an additive to achieve the highly dispersed metal-supported catalysts. This study aimed to investigate the effect of citric acid concentration on the preparation of the highly dispersed Ni catalysts on mesoporous silica (SBA-15) for the dry reforming of methane. A series of Ni/SBA-15 catalysts with citric acid were prepared using the acid-assisted incipient wetness impregnation method, and the Ni/SBA-15 catalyst as a reference was synthesized via the impregnation method. First of all, the citric acid addition during the catalyst synthesis step regardless of its concentration resulted in highly dispersed Ni particles of ~4–7 nm in size in Ni/SBA-15 catalysts, which had a superior and stable catalytic performance in the dry reforming of methane (93% of CO2 conversion and 86% of CH4 conversion). In addition, the amount of coke formation was much lower in a series of Ni/SBA-15 catalysts with citric acid (~2–5 mgcoke gcat−1 h−1) compared to pristine Ni/SBA-15 catalysts (~22 mgcoke gcat−1 h−1). However, when the concentration of citric acid became higher, the more free NiO species that formed on the SBA-15 support, leading to large Ni particles after the stability test. The addition of citric acid is a very clear strategy for making highly dispersed catalysts, but its concentration needs to be carefully controlled.

Capacitive deionization (CDI) technology is currently considered a potential candidate for brackish water desalination. In this study, we designed iron oxide nanoparticle-incorporated activated carbon (AC/Fe2O3) via a facile and cost-effective hydrothermal process. The as-synthesized material was characterized using several techniques and tested as electrodes in CDI applications. We found that the distinctive properties of the AC/Fe2O3 electrode, i.e., high wettability, high surface area, unique structural morphology, and high conductivity, resulted in promising CDI performance. The electrosorptive capacity of the AC/Fe2O3 nanocomposite reached 6.76 mg g−1 in the CDI process, with a high specific capacitance of 1157.5 F g−1 at 10 mV s−1 in a 1 M NaCl electrolyte. This study confirms the potential use of AC/Fe2O3 nanocomposites as viable electrode materials in CDI and other electrochemical applications.

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