An aqueous solution of aniline was oxidized in supercritical water with a flow reactor under the conditions of 25 MPa, 300% excess oxygen, 2.351×10 -4 mol·L -1 aniline .GC-MS analysis of the oxidation produc...An aqueous solution of aniline was oxidized in supercritical water with a flow reactor under the conditions of 25 MPa, 300% excess oxygen, 2.351×10 -4 mol·L -1 aniline .GC-MS analysis of the oxidation products extracted from the aqueous reactor effluent permitted identification of compounds such as azobenzene, phenazine and acetic acid. The products could be classified as dimers,single-ring or ring-opening produces,carboxylic acids and ultimate products.The contents of dimers (such as azobenzene and phenazine) were greater than other products.A reaction network consistent with the experimental observations was developed. The study revealed that aniline might be oxidized to ultimate products through two parallel pathways. The formation of dimers such as azobenzene, phenazine and the further oxidation of these dimers were the main pathways. It was indicated experimentally that the rate controlling step of aniline oxidation was the further oxidation of azobenzene and phenazine, but not the further oxidation of organic acid such as acetic acid, formic acid and so on.展开更多
Electrocatalysis is deemed as a promising approach for sustainable energy conversion and chemical production.Although a variety of cathode reactions(e.g.,hydrogen evolution and CO_(2)/N_(2)reduction)produce valuable f...Electrocatalysis is deemed as a promising approach for sustainable energy conversion and chemical production.Although a variety of cathode reactions(e.g.,hydrogen evolution and CO_(2)/N_(2)reduction)produce valuable fuels and chemicals,the extensively studied oxygen evolution reaction(OER)at anode only generates O_(2),which is not a high-value product.Substituting the OER with thermodynamically more favorable biomass derivative oxidation reactions(BDORs)not only enables energy-saving electrocatalysis,but also provides value-added anode products.Recent achievements have demonstrated that non-noble electrocatalysts are promising for BDORs.Herein,we provide a comprehensive review on recent achievements in the field of electrochemical BDORs catalyzed by non-noble catalysts.We start by summarizing the electrocatalytic oxidation of different types of biomass-derived substrates,aiming to show the advantages of the electrocatalytic pathway and to introduce the state-of-the-art non-noble catalysts.The reaction mechanisms of non-noble-material-catalyzed BDORs are then summarized and classified into three types according to the acceptor of hydrogen species during the dehydrogenation of biomass derivatives.Subsequently,discussions are devoted to the strategies for promoting the performances of non-noble electrocatalysts.Finally,we propose our opinions regarding future trends and major challenges in this field.展开更多
文摘An aqueous solution of aniline was oxidized in supercritical water with a flow reactor under the conditions of 25 MPa, 300% excess oxygen, 2.351×10 -4 mol·L -1 aniline .GC-MS analysis of the oxidation products extracted from the aqueous reactor effluent permitted identification of compounds such as azobenzene, phenazine and acetic acid. The products could be classified as dimers,single-ring or ring-opening produces,carboxylic acids and ultimate products.The contents of dimers (such as azobenzene and phenazine) were greater than other products.A reaction network consistent with the experimental observations was developed. The study revealed that aniline might be oxidized to ultimate products through two parallel pathways. The formation of dimers such as azobenzene, phenazine and the further oxidation of these dimers were the main pathways. It was indicated experimentally that the rate controlling step of aniline oxidation was the further oxidation of azobenzene and phenazine, but not the further oxidation of organic acid such as acetic acid, formic acid and so on.
基金supported by the National Natural Science Foundation of China (21978147 and 21935001)Haihe Laboratory of Sustainable Chemical Transformationssupported by the Shuimu Tsinghua Scholar Program (2021SM072)
文摘Electrocatalysis is deemed as a promising approach for sustainable energy conversion and chemical production.Although a variety of cathode reactions(e.g.,hydrogen evolution and CO_(2)/N_(2)reduction)produce valuable fuels and chemicals,the extensively studied oxygen evolution reaction(OER)at anode only generates O_(2),which is not a high-value product.Substituting the OER with thermodynamically more favorable biomass derivative oxidation reactions(BDORs)not only enables energy-saving electrocatalysis,but also provides value-added anode products.Recent achievements have demonstrated that non-noble electrocatalysts are promising for BDORs.Herein,we provide a comprehensive review on recent achievements in the field of electrochemical BDORs catalyzed by non-noble catalysts.We start by summarizing the electrocatalytic oxidation of different types of biomass-derived substrates,aiming to show the advantages of the electrocatalytic pathway and to introduce the state-of-the-art non-noble catalysts.The reaction mechanisms of non-noble-material-catalyzed BDORs are then summarized and classified into three types according to the acceptor of hydrogen species during the dehydrogenation of biomass derivatives.Subsequently,discussions are devoted to the strategies for promoting the performances of non-noble electrocatalysts.Finally,we propose our opinions regarding future trends and major challenges in this field.
