Synchronously Achieving Highly Efficient Hydrogen Evolution and High-Yield Synthesis of Glucaric Acid by MOF Nanorod Arrays

Highly energy-efficient and stable electrocatalysts for hydrogen evolution reaction (HER) are very important for sustainable and clean energy technologies, but are limited by sluggish anodic oxygen evolution reaction (OER). In this work, we develop a strategy using a self-supported MOF nanorod arrays, [Ni-3(BTC)(2)/NiF] as bifunctional catalyst for integrating energy-saving HER and replacement of OER by the thermodynamically more favorable electro-oxidation of sodium gluconate (ECSG) to high-value glucaric acid. The Ni-3(BTC)(2)/NiF only require a cell voltage of 1.22 V to drive 100 mA cm(-2) in KOH solution with sodium gluconate (SG), which is significantly reduced by 400 mV relative to the alkaline solution without SG. The assembled [Ni-3(BTC)(2)/NiF parallel to Ni-3(BTC)(2)/NiF] couple behaves nearly 100% Faradic efficiency for HER at the cathode and SG conversion of 100% with glucaric acid selectivity of 97.9% at the anode, and long-term durability. Such an integration of HER and oxidative biomass to high-value-added chemical provides a new way to maximize the energy conversion efficiency. (C) 2019 The Electrochemical Society.