Copper-Iron-Zinc-Cerium oxide compositions as most suitable catalytic materials for the synthesis of green fuels via CO2 hydrogenation

[Ce3+-OV-Ce4+] Located Surface-Distributed Sheet Cu-Zn-Ce Catalysts for Methanol Production by CO2 Hydrogenation

The metal-support interaction is crucial for the performance of Cu-based catalysts. However, the distinctive properties of the support metal element itself are often overlooked in catalyst design. In this paper, a sheet Cu-Zn-Ce with [Ce3+-OV-Ce4+] located on the surface was designed by the sol-gel method. Through EPR and X-ray photoelectron spectroscopy (XPS), the relationship between the content of oxygen vacancies and Ce was revealed. Ce itself induces the generation of [Ce3+-OV-Ce4+]. Through ICP-MS, XPS, and SEM-mapping, the Ce-induced formation of [Ce3+-OV-Ce4+] located on the catalyst surface was demonstrated. CO2-TPD and DFT calculations further revealed that [Ce3+-OV-Ce4+] enhanced CO2 adsorption, leading to a 10% increase in methanol selectivity compared to Cu-Zn-Ce synthesized via the coprecipitation method.

Bifunctional CuO-Ag/KB Catalyst for the Electrochemical Reduction of CO2 in an Alkaline Solid-State Electrolysis Cell

The conversion of carbon dioxide into value-added products is progressively gaining momentum. Several strategies have been used to develop technologies that reduce the net emissions of CO2. The utilisation of CO2 could either contribute to carbon recycling. In this paper, the transformation of CO2 was investigated in a coelectrolysis cell constituted of a solid polymer electrolyte, a carbon-supported CuO-Ag composite cathode and NiFeOx anode. Noncritical raw materials were synthesised according to the oxalate method and investigated in an alkaline environment. Low-carbon alcohols were obtained with a specific selectivity for ethanol and methanol over the CuO-Ag/KB cathode. The reaction rates at 1.6 V and 1.8 V cell voltages have been determined in steady-state experiments using NaHCO3 supporting electrolyte recirculated at the anode.

Accelerated Redox Cycles of Fe(III)/Fe(II) and Cu(III)/Cu(II) by Photo-Induced Electron from N-CQDs for Enhanced Photo-Fenton Capability of CuFe-LDH

Layered double hydroxide (LDH) materials have shown charming photo-Fenton capability for the treatment of refractory organic wastewater. In this study, CuFe-LDH hybridized with N-doped carbon quantum dots (N-CQDs) was investigated to further enhance the photo-Fenton capability. The results showed that the assembly techniques of coprecipitation and the hydrothermal method could synthesize the target material, CuFe-LDH/N-CQDs, successfully. CuFe-LDH/N-CQDs could possess a 13.5% higher methylene blue (MB) removal rate than CuFe-LDH in 30 min due to the accelerated redox cycles of Fe(III)/Fe(II) and Cu(III)/Cu(II), resulting from the photo-induced electron transfer from N-CQDs to CuFe-LDH via a d–π conjugation electronic bridge. Moreover, CuFe-LDH/N-CQDs has excellent photo-Fenton capability in the pH range of 2–11, even after being reused five times. This study would provide an efficient and stable photo-Fenton catalyst for the treatment of refractory organic wastewater.

Effect of Hematite Doping with Aliovalent Impurities on the Electrochemical Performance of α-Fe2O3@rGO-Based Anodes in Sodium-Ion Batteries

The effect of the type of dopant (titanium and manganese) and of the reduced graphene oxide content (rGO, 30 or 50 wt %) of the α-Fe₂O₃@rGO nanocomposites on their microstructural properties and electrochemical performance was investigated. Nanostructured composites were synthesized by a simple one-step solvothermal method and evaluated as anode materials for sodium ion batteries. The doping does not influence the crystalline phase and morphology of the iron oxide nanoparticles, but remarkably increases stability and Coulombic efficiency with respect to the anode based on the composite α-Fe₂O₃@rGO. For fixed rGO content, Ti-doping improves the rate capability at lower rates, whereas Mn-doping enhances the electrode stability at higher rates, retaining a specific capacity of 56 mAhg^-1 at a rate of 2C. Nanocomposites with higher rGO content exhibit better electrochemical performance.