Preparation Of Ni-based Nanocatalyst For Efficient Electrochemical Oxidation Of Benzyl Alcohol

In the context of low-carbon and energy transition,hydrogen production by electrolysis of water is currently one of the most suitable hydrogen energy production methods in line with our country’s development strategy.Recently,scientific community has devoted to intense research efforts toward chemical-assisted HER,especially the alcohol oxidation assisted HER.For primary alcohols,most of them could be oxidized at an anodic potential between 0.5～1.3 V（vs.saturated calomel electrode,SCE）.Therefore,it can be used as anode raw material to participate in the reaction and then replace the oxygen evolution reaction（OER）.This method can not only reduce the large overpotential and energy consumption in the water electrolysis process,but also produce higher value-added aldehydes and/or carboxylic acids.According to investigations and studies,our country has an overcapacity of BA.On the other hand,higher value-added benzoic acid and benzaldehyde are produced by traditional catalytic technology,which requires high temperature,high pressure and high energy consumption reaction conditions.Therefore,designing the BA oxidation reaction into the hybrid water electrolysis system will serve multiple purposes.The main research contents of this paper are as follows:1.Ni@NC-200,Ni@NC-280,Ni@NC-500 catalysts with different Ni sizes were synthesized by wet chemistry and calcination reduction method,which were used for the electrocatalytic oxidation of BA.The size effect of Ni-based nanocatalysts on the electrooxidation activity of organic compounds was investigated,and the structure-activity relationship were further explore.It is shown that the intermediate size Ni@NC-280 has the highest catalytic activity,in which.a current density of 10 m A﹒cm^-2can be obtained with only 1.35 V.Mechanistic studies reveal that Ni@NC-280catalyst can facilitate the adsorption and activation of reactants,and the benzene ring played an auxiliary adsorption role in the electrocatalytic oxidation of BA.This work has certain guiding significance for improving the efficiency of organic matter oxidation and promoting hydrogen production through material design methods.2.The Ru-Ni（OH）₂/NF catalyst was synthesized by a simple impregnation-stirring method,and used for the electrocatalytic oxidation reaction of BA,HER,and electrochemical water splitting.The catalyst has the characteristics of simple synthesis and high-efficiency catalysis.The electrocatalytic oxidation of anode BA to benzoic acid（BZA）has a conversion rate of 100%and a Faraday efficiency of 98%.In the alkaline hydrogen evolution reaction（HER）,the overpotential at the current density of10 m A﹒cm^-2 is only 66 m V.In a two-electrode system containing BA,a current density of 10 m A﹒cm^-2can be reached at a voltage of 1.4 V,while 1.56 V is required in a system without BA.The above data indicate that Ru-doped Nickel hydroxide nanosheet catalyst has excellent bi-functionality.The catalyst oxidized benzyl alcohol on the anode to reduce potential,and had a low HER overpotential on the cathode,thus accelerating the process of water electrolysis.This paper provides a new idea for rational design of simple and efficient new electrolytic water catalyst by exploring the structure-activity relationship of catalyst.