Regeneration of deactivated CeCo O2 catalyst by simple thermal treatment

Site-Specific Electron-Driving Observations of CO2 -to-CH4 Photoreduction on Co-Doped CeO2 /Crystalline Carbon Nitride S-Scheme Heterojunctions

Photoexcited dynamic modulation, maximizing the effective utilization of photoinduced electron-hole pairs, dominates the multiple electrons-involving reduction pathways for terminal CH₄ evolution during CO₂ photoreduction. Yet, the site-specific regulation of directional charge transfer by modification of an S-scheme heterojunction has seldom been discussed. Herein, an atomic-level tailoring strategy by anchoring single-atomic Co into CeO₂ co-catalyst rather than carbon nitride supports, which can selectively favor CO₂ -to-CH₄ photoreduction, is reported. Through in situ dynamic tracking investigations, this study identifies that surface Co-embedded bimetallic CeCo conjunction is the key feature driving a strong interconnection of dynamical charge states through S-scheme heterojunctions. The Co-embedded modification into CeO₂ co-catalysts is demonstrated to have a critical effect on directional charge control, accelerating the driving of electrons from the carbon nitride donations to site-specific Co hubs, which thereby promotes electronic transferability for electrons-involving CH₄ formation. As a result, an unprecedented CH₄ yield (181.7 µmol g^-1 ) is obtained with a high turnover number (411.4) through a fully gas-solid reaction, demonstrating its potential toward targeted CH₄ formation without adding any sacrificial agent.

Adsorption of Yttrium Ions on 3-Amino-5-Hydroxypyrazole Impregnated Bleaching Clay, a Novel Sorbent Material

In this work, spent bleaching clay (SBC) was treated with ethyl acetate and impregnation with 3-amino-5-hydroxypyrazole (AHIBC) that utilized as economical sorbent material. The uptake of yttrium ions from aqueous solution using AHIBC was studied under batch process as a function of pH of the solution, contact time, adsorbent dosage, Yttrium ions concentration, and ambient temperature. The adsorption equilibrium was achieved at the value of pH = 6.0 and agitation time of 60 min at room temperature. The utmost adsorption capacity of Y(III) ions on AHIBC was 171.32 mg·g−1. Kinetic, isotherm, and thermodynamic models were applied to the experimental data obtained. Adsorption follows a pseudo–second–order kinetic model, while the adsorption isotherm fits the Langmuir model. A negative value of Gibbs free energy ΔG° revealed that the adsorption of the Y ions on the AHIBC adsorbent was spontaneously in nature. In addition, the electrostatic interaction process between the metal ions and AHIBC was favorable. The negative value of ΔH° states that Y ions adsorption was an exothermic process. Desorption efficiency reduced from 97% to 80% after eight consecutive rounds.