Houjun Chen’s research while affiliated with Hunan University and other places

Integrating anodic biomass valorization with carbon dioxide electroreduction (CO2RR) can produce value‐added chemicals on both the cathode and anode; however, anodic oxidation still suffers from high overpotential. Herein, a photothermal‐assisted method was developed to reduce the potential of 5‐hydroxymethyl furfural (HMF) electrooxidation. Capitalizing on the copious oxygen vacancies, defective Co3O4 (D‐Co3O4) exhibited a stronger photothermal effect, delivering a local temperature of 175.47 °C under near infrared light illumination. The photothermal assistance decreased the oxidation potential of HMF from 1.7 V over pristine Co3O4 to 1.37 V over D‐Co3O4 to achieve a target current density of 30 mA cm⁻², with 2,5‐furandicarboxylic acid as the primary product. Mechanistic analysis disclosed that the photothermal effect did not change the HMF oxidation route but greatly enhanced the adsorption capacity of HMF. Meanwhile, faster electron transfer for direct HMF oxidation and the surface conversion to cobalt (oxy)hydroxide, which contributed to indirect HMF oxidation, was observed. Thus, rapid HMF conversion was realized, as evidenced by in situ surface‐enhanced infrared spectroscopy. Upon coupling cathodic CO2RR with an atomically dispersed Ni−N/C catalyst, the Faradaic efficiencies of CO (cathode) and 2,5‐furandicarboxylic acid (FDCA, anode) exceeded 90.0 % under a low cell potential of 1.77 V.

High-purity ethylene production from CO2 electroreduction (CO2RR) is a coveted, yet arduous feat because the product stream comprises a blend of unreacted CO2, H2, and other off-target CO2 reduction products. Here we present an indirect reduction strategy for CO2-to-ethylene conversion, one that employs 2-bromoethanol (Br-EO) as a mediator. Br-EO is initially generated from CO2RR and subsequently undergoes reduction to ethylene without the need for energy-intensive separation steps. The optimized AC-Ag/C catalyst with Cl incorporation reduces the energy barrier of the debromination step during Br-EO reduction, and accelerates the mass-transfer process, delivering a 4-fold decrease of the relaxation time constant. Resultantly, AC-Ag/C achieved a FEethylene of over 95.0 ± 0.36% at a low potential of −0.08 V versus reversible hydrogen electrode (RHE) in an H-type cell with 0.5 M KCl electrolyte, alongside a near 100% selectivity within the range of −0.38 to −0.58 V versus RHE. Through this indirect strategy, the average ethylene purity within 6-hour electrolysis was 98.00 ± 1.45 wt%, at −0.48 V (vs RHE) from the neutralized electrolyte after CO2 reduction over the Cu/Cu2O catalyst in a flow-cell.

Single-atom, confined in crystalline porous materials such as metal-organic framework (MOF), features unparalleled multidimensional interactions with the molecular wall of the nano-cavity, showcasing a synergistic catalytic effect. Nevertheless, the insulating...

Balancing the activation of H2O is crucial for highly selective CO2 electroreduction (CO2RR), as the protonation steps of CO2RR require fast H2O dissociation kinetics, while suppressing hydrogen evolution (HER) demands slow H2O reduction. We herein proposed one molecular engineering strategy to regulate the H2O activation using aprotic organic small molecules with high Gutmann donor number as a solvation shell regulator. These organic molecules occupy the first solvation shell of K⁺ and accumulate in the electrical double layer, decreasing the H2O density at the interface and the relative content of proton suppliers (free and coordinated H2O), suppressing the HER. The adsorbed H2O was stabilized via the second sphere effect and its dissociation was promoted by weakening the O−H bond, which accelerates the subsequent *CO2 protonation kinetics and reduces the energy barrier. In the model electrolyte containing 5 M dimethyl sulfoxide (DMSO) as an additive (KCl‐DMSO‐5), the highest CO selectivity over Ag foil increased to 99.2 %, with FECO higher than 90.0 % within −0.75 to −1.15 V (vs. RHE). This molecular engineering strategy for cation solvation shell can be extended to other metal electrodes, such as Zn and Sn, and organic molecules like N,N‐dimethylformamide.

Balancing the activation of H 2 O is crucial for highly selective CO 2 electroreduction (CO 2 RR), as the protonation steps of CO 2 RR require fast H 2 O dissociation kinetics, while suppressing hydrogen evolution (HER) demands slow H 2 O reduction. We herein proposed one molecular engineering strategy to regulate the H 2 O activation using aprotic organic small molecules with high Gutmann donor number as a solvation shell regulator. These organic molecules occupy the first solvation shell of K ⁺ and accumulate in the electrical double layer, decreasing the H 2 O density at the interface and the relative content of proton suppliers (free and coordinated H 2 O), suppressing the HER. The adsorbed H 2 O was stabilized via the second sphere effect and its dissociation was promoted by weakening the O−H bond, which accelerates the subsequent *CO 2 protonation kinetics and reduces the energy barrier. In the model electrolyte containing 5 M dimethyl sulfoxide (DMSO) as an additive (KCl‐DMSO‐5), the highest CO selectivity over Ag foil increased to 99.2 %, with FE CO higher than 90.0 % within −0.75 to −1.15 V (vs. RHE). This molecular engineering strategy for cation solvation shell can be extended to other metal electrodes, such as Zn and Sn, and organic molecules like N,N‐dimethylformamide.

The local microenvironment of single-atom electrocatalysts (SACs) governs their activity and selectivity. While previous studies have focused on the first coordination shell (FCS) of metal centers, functional species beyond FCS...