Electrocatalytic Reactions for Converting CO2 to Value-Added Products: Recent Progress and Emerging Trends

Production of H2 and Glucaric Acid Using Electrocatalyst Glucose Oxidation by the Ta NiFe LDH Electrode

The slow anodic oxygen evolution reaction (OER) significantly limits electrocatalytic water splitting for hydrogen production. We proposed the electrocatalyst for glucose oxidation by Ta-doping NiFe LDH nanosheets to simultaneously obtain glucaric acid (GRA) and hydrogen gas as a useful byproduct. Superior glucose oxidation reaction (GOR) activity is demonstrated by the optimized Ta-NiFe LDH, which has a low overpotential of 192 mV, allowing for a small Tafel slope of 70 mV dec-1 and a current density of 50 mA cm-2. The Ta NiFe LDH-oxidized glucose to GRA with a 72.94% yield and 64.3% Faradaic efficiency at 1.45 VRHE. Herein, we report the Ta NiFe LDH/NF electrode for the GOR&hydrogen evolution reaction (HER), which exhibits a cell voltage of 1.62 V to reach a current density of 10 mA cm-2, which is 250 mV lower compared to OER&HER (1.87 V). This study reveals that GOR is an energy-efficient and cost-effective method for producing H2 and valorizing biomass.

Enhanced CO2 Capture through SAPO-34 Impregnated with Ionic Liquid

The concurrent utilization of an adsorbent and absorbent for carbon dioxide (CO2) adsorption with synergistic effects presents a promising technique for CO2 capture. Here, 1-butyl-3-methylimidazole acetate ([Bmim][Ac]), with a high affinity for CO2, and the molecular sieve SAPO-34 were selected. The impregnation method was used to composite the hybrid samples of [Bmim][Ac]/SAPO-34, and the pore structure and surface property of prepared samples were characterized. The quantity and kinetics of the sorbed CO2 for loaded samples were measured using thermogravimetric analysis. The study revealed that SAPO-34 could retain its pristine structure after [Bmim][Ac] loading. The CO2 uptake of the loaded sample was 1.879 mmol g-1 at 303 K and 1 bar, exhibiting a 20.6% rise compared to that of the pristine SAPO-34 recording 1.558 mmol g-1. The CO2 uptake kinetics of the loaded samples were also accelerated, and the apparent mass transfer resistance for CO2 sorption was significantly reduced by 11.2% compared with that of the pure [Bmim][Ac]. The differential scanning calorimetry method revealed that the loaded sample had a lower CO2 desorption heat than that of the pure [Bmim][Ac], and the CO2 desorption heat of the loaded samples was between 30.6 and 40.8 kJ mol-1. The samples exhibited good cyclic stability. This material displays great potential for CO2 capture applications, facilitating the reduction of greenhouse gas emissions.

Comprehensive Insights and Advancements in Gel Catalysts for Electrochemical Energy Conversion

Continuous worldwide demands for more clean energy urge researchers and engineers to seek various energy applications, including electrocatalytic processes. Traditional energy-active materials, when combined with conducting materials and non-active polymeric materials, inadvertently leading to reduced interaction between their active and conducting components. This results in a drop in active catalytic sites, sluggish kinetics, and compromised mass and electronic transport properties. Furthermore, interaction between these materials could increase degradation products, impeding the efficiency of the catalytic process. Gels appears to be promising candidates to solve these challenges due to their larger specific surface area, three-dimensional hierarchical accommodative porous frameworks for active particles, self-catalytic properties, tunable electronic and electrochemical properties, as well as their inherent stability and cost-effectiveness. This review delves into the strategic design of catalytic gel materials, focusing on their potential in advanced energy conversion and storage technologies. Specific attention is given to catalytic gel material design strategies, exploring fundamental catalytic approaches for energy conversion processes such as the CO2 reduction reaction (CO2RR), oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and more. This comprehensive review not only addresses current developments but also outlines future research strategies and challenges in the field. Moreover, it provides guidance on overcoming these challenges, ensuring a holistic understanding of catalytic gel materials and their role in advancing energy conversion and storage technologies.