Aminoxyl-mediated electrocatalysis offers a sustainable approach for the oxidation of alcohols to carboxylic acids. However, the high dosage of aminoxyl radicals and the limiting current density hinder the practicality of industrial application. Herein, a nickel-based electrocatalyst (Ni-tpdc) was synthesized on a three-dimensional porous graphite felt substrate. Taking advantage of the synergistic effect of the electrochemically activated Ni-tpdc/GF electrocatalyst with 4-acetamido-TEMPO, the yield of 4-pyridinecarboxylic acid was up to 99% with only 1 mol% ACT. A series of in situ measurements showed that NiOOH enhanced the activity of the intrinsic electrocatalyst. Additionally, the synergistic system was extended to the oxidation of various heterocyclic alcohols. The scale-up synthesis of chiral acid (LEV-CO 2H) was achieved in an improved electrolyzer with a yield of 95.4%, enantiomeric retention of 99.2%, and space-time yield of 34.12 kg/(m 3·h). The practicality and effectiveness of this synergistic electrocatalytic strategy in practical electrosynthesis was further demonstrated.

Electrochemical synthesis of green oxidants O3 and H2O2 is valuable for applications, but challenges persist in enhancing the O3 and H2O2 generation activity and combined application. Herein, we modulate the surface Ni active sites and oxygen vacancy defects content in Ni-Sb-SnO2 electrocatalysts to enhance selectivity for electrochemical ozone generation (EOP) and two-electron electrochemical oxygen reduction reactions (2e⁻ ORR). The Ni active sites and oxygen vacancy defects enriched electrocatalysts resulting in an ozone faradaic efficiency of 48.1%, while non-enriched electrocatalyst obtained 90% selectivity for H2O2. Theoretical calculations revealed that Ni-Sb-SnO2 efficiently captures O2 with defective Ovac2 stabilize intermediates, facilitating O3 and H2O2 synthesis. Moreover, concerted EOP and 2e⁻ ORR enable concurrent generation of O3 and H2O2 for efficient synergistic degradation of organic pollutants, while attenuating the energy demands of the electrolyzer. This study provides an appealing strategy for the simultaneous production of O3 and H2O2 with applications in wastewater treatment.

The exploration of efficient and environmentally friendly oxidation method is highly desirable to overcome the critical problems of poor selectivity and heavy metal contamination for the fine chemicals industry. Herein, a self-supported 3D Se-Ni5P4 nanosheet electrocatalyst was rationally designed and fabricated. Benefiting from the synergistic effect of aminoxyl radical and mesoporous Se-Ni5P4/GF, an excellent performance of ≥98% selectivity and 33.12 kg/(m3·h) space-time yield was obtained for sterol intermediate oxidation with the enhanced mass transfer effect of the continuous flow system. The doping of anionic selenium and phosphorus modulated the electronic structure of Se-Ni5P4, and the oxyhydroxides generated by surface reconstruction accelerated the turnover of TEMPO, thereby enhancing the intrinsic electrocatalytic activity. A scale-up experiment was conducted with stacked-flow electrolyzer demonstrated the application potential. This work provided an efficient synergistic electrocatalytic strategy to facilitate rapid electron and mass transfer for electrochemical alcohol oxidation and highlighted the potential for practical electrosynthesis applications.