CoNi-MOF-74/NF Derived CoNi@C/NF Hybrid for Efficient Electrosynthesis of Organics

Electrocatalytic organic synthesis as a green and sustainable synthesis method, has a great potential to replace traditional synthetic method of fine chemicals in industry. To maximize the energy investment, achieving simultaneous conversion of organics at two electrodes is an effective solution. The required electrocatalysts should be effective on two reactions at both anode and cathode, and balance the total electron transfer numbers. However, most reported catalysts are monofunctional and high selectivity of target products is difficult to control. Therefore, it is necessary to develop multi-functional electrocatalysts with low-cost, high efficiency and long-life. In this work, CoNi-MOF-74/NF composite was obtained by in-situ growth of bimetallic metal-organic framework (CoNi-MOF) on nickel foam (NF) via one-step solvothermal method. NF provided nickel source and template. Then the CoNi-MOF-74/NF was calcined to give nickel foam stabilized CoNi alloy nanoparticles coated with graphite carbon layer under 20%H-2/Ar atmosphere at 400 degrees C. The CoNi@C/NF hybrid shown excellent catalytic performance for the isolated electrooxidation of benzyl alcohol to benzoic acid and the electroreduction of nitrobenzene (NP) to aniline using three-electrode system. Furthermore, the hybrid achieved 99% conversion for the pairing reaction constructed by the electrocatalytic oxidation of alcohol at anode coupling with the electroreduction of nitrobenzene at cathode. Thus, more value-added organic products could be obtained using limited catalyst and electricity, creating a sustainable organic synthesis system. Furthermore, the CoNi@C/NF performs good catalytic stability at two electrodes even after six cycles. For comparison, various contrast catalysts including monometallic Ni@C/NF, Co@C, and CoNi@C have been also synthesized. The optimal activity of CoNi@C/ NF mainly attributes to the synergistic catalysis between Co and Ni, good electric conductivity of NF and graphitic carbon, as well as the porous porosity from NF and porous carbon framework. This study opens up a novel way for designing multifunctional electrode materials in the green synthesis of fine chemicals from MOFs.