A weak aspect of the electro-Fenton (EF) oxidation of contaminants is the dependence of the Fenton reaction on acidic pH values. Therefore, the rationale of this work was to develop a novel catalyst capable of promoting the EF oxidation process at near-neutral and basic pH values. In this framework, rhombohedral FeCO₃ was synthesized hydrothermally and used as a catalyst in the EF oxidation of p-benzoquinone (BQ). The catalyst was characterized using various surface and spectroscopic methods. Moreover, the effects of applied current (100–500 mA), time (1–9 h), catalyst dosage (0.25–1.00 g L⁻¹), and initial concentration of BQ (0.50–1.00 mM) on the total organic carbon removal efficiency were determined. The results indicated that a 400 mA current was sufficient for a 95% total organic carbon removal and that the increase in catalyst dosage had a positive effect on the mineralization of BQ. It was determined that at pH 3, FeCO₃ behaved like a homogeneous catalyst by releasing Fe³⁺ ions; whereas, at the pH range of 5–7, it shifted to a homogeneous/heterogeneous catalyst. At pH 9, it worked solely as a heterogeneous catalyst due to the decrease of Fe ions passing into the solution. Finally, the spent catalyst did not undergo structural deformations after the EF treatment at higher pH values and could be regenerated and used several times

This study focused on the preparation and characterization of Pd-Ni bimetallic catalysts supported on cerium-coated cordierite for carbon monoxide oxidation in a batch system. Using techniques such as XRD, FTIR, SEM/EDS, and BET, we confirmed successful metal loading and strong interactions between the metals and the support. The BET results showed that catalysts with balanced Pd and Ni ratios, especially Ni50, had larger surface areas, likely due to synergistic effects. Catalytic tests carried out at 300 °C demonstrated that these bimetallic catalysts performed nearly as well as the pure Pd catalyst in converting CO, while also benefiting from the inherent activity of the cerium-coated support. Overall, this study suggests that combining Pd with Ni can reduce the amount of precious metal needed without sacrificing efficiency, pointing to a more cost-effective solution for emission control applications.

In this study, natural sand was used as a low-cost and sustainable support material for generating an original catalyst. It was subsequently modified using cerium oxide and loaded with platinum. Characterization results showed that the cerium coating significantly increased the surface area of the support material to 13.36 m ² /g, while XRD analyses confirmed the presence of silica and ceria phases in the structure. This catalyst was used to generate hydrogen-rich gas mixtures via the aqueous-phase reforming (APR) of methanol. In order to optimize reaction performance, Response Surface Methodology (RSM) was used to evaluate the effects of temperature, reaction time, and catalyst amount. A maximum gas volume of 360 mL was obtained under optimum conditions, which included a temperature of 300 °C, a reaction period of 1 h, and a catalyst amount of 1 g. The catalyst showed remarkable hydrogen selectivity with a hydrogen yield of 77.38% and a carbon monoxide yield of 0.13% under these conditions. The study demonstrated the potential of cerium-coated natural sand as an effective and environmentally friendly support for platinum-based catalysts in clean hydrogen production from methanol.