Density-controlled metalloporphyrin with mutated surface via pulsed laser for oxidative refining of alcohols to benzoic acid and H2 production using linear tandem electrolysis

Abstract

A highly selective and multifunctional electrocatalyst is constructed by combining a single-phase Ni3S2 obtained via pulsed laser ablation in liquids (PLAL) with different contents of nickel tetraphenylporphyrin (NiTPP) complex. The catalytic performance is assessed in consecutive hydrogen (HER) and oxygen evolution (OER), as well as benzyl alcohol (B.Alc) oxidation reactions (AOR). The optimal NiS-NiTPP10% exhibits the highest activity with overpotentials of 435, 320, and 170 mV, respectively. Moreover, NiS-NiTPP10% favors alcohol oxidation reaction and produces benzoic acid (B.Ac) at a yield rate of 2.23 mM h−1 cm−2 with 100% mass balance, 98.3% Faradaic efficiency (FE), and 99.8% selectivity. Finally, the system with simultaneous H2 evolution and value-added B.Ac production is successfully employed in a NiS-NiTPP10%||NiS-NiTPP10% electrolyzer, resulting in a high FE of 81% and 99%, and a yield rate of 0.42 and 4.03 mM h−1 cm−2, respectively, at a lower cell voltage of 193 mV than the standard water electrolyzer. The pyrrole rings of NiTPP could act as the terminal for the B.Alc molecule, and the Ni2+/Ni3+ redox pair of Ni3S2 could accelerate the oxidation process. Hence, both Ni3S2 and NiTPP boost the performance of NiS-NiTPP10% via charge-density modulation and strong synergistic effects. © 2024 Elsevier B.V.