Ammonia(NH_(3))is a multifunctional compound that is an important feedstock for the agricultural and pharmaceutical industries and attractive energy storage medium.At present,NH_(3)synthesis is highly dependent on the...Ammonia(NH_(3))is a multifunctional compound that is an important feedstock for the agricultural and pharmaceutical industries and attractive energy storage medium.At present,NH_(3)synthesis is highly dependent on the conventional Haber–Bosch process that operates under harsh conditions,which consumes large quantities of fossil fuels and releases a large amount of carbon dioxide.As an alternative,electrosynthesis is a prospective method for producing NH_(3)under normal temperature and pressure conditions.Although electrocatalytic nitrogen reduction to ammonia has attracted considerable attentions,the low solubility of N_(2)and high N≡N cracking energy render the achievements of high NH_(3) yield rate and Faradaic efficiency difficult.Nitrate and nitrite(NO_(x)^(-))are common N-containing pollutants.Due to their high solubilities and low dissociation energy of N=O,NO_(x)^(-)−are ideal raw materials for NH_(3) production.Therefore,electrocatalytic NO_(x)^(-)−reduction to NH_(3)(eNO_(x)RR)is a prospective strategy to simultaneously realise environmental protection and NH_(3) synthesis.This review offers a comprehensive understanding of the thriving eNO_(x)RR under ambient conditions.At first,the popular theory and mechanism of eNO_(x)RR and a summary of the measurement system and evaluation criteria are introduced.Thereafter,various strategies for developing NO_(x)−reduction catalysts are systematically presented and discussed.Finally,the challenges and possible prospects of electrocatalytic NO_(x)^(-1) reduction are outlined to facilitate energy-saving and environmentally friendly large-scale synthesis of NH_(3) in the future.展开更多
This study introduces a pre-orthogonal adaptive Fourier decomposition(POAFD)to obtain approximations and numerical solutions to the fractional Laplacian initial value problem and the extension problem of Caffarelli an...This study introduces a pre-orthogonal adaptive Fourier decomposition(POAFD)to obtain approximations and numerical solutions to the fractional Laplacian initial value problem and the extension problem of Caffarelli and Silvestre(generalized Poisson equation).As a first step,the method expands the initial data function into a sparse series of the fundamental solutions with fast convergence,and,as a second step,makes use of the semigroup or the reproducing kernel property of each of the expanding entries.Experiments show the effectiveness and efficiency of the proposed series solutions.展开更多
该研究采用水提醇沉法从盐制巴戟天中提取粗多糖(SMP),经DEAE-52纤维素柱和葡聚糖凝胶Sephadex G 100柱分离纯化得到多糖(SMP-4),采用红外光谱、高效凝胶渗透凝胶色谱、气相色谱和核磁共振波对SMP-4进行结构表征,并以RAW264.7巨噬细胞...该研究采用水提醇沉法从盐制巴戟天中提取粗多糖(SMP),经DEAE-52纤维素柱和葡聚糖凝胶Sephadex G 100柱分离纯化得到多糖(SMP-4),采用红外光谱、高效凝胶渗透凝胶色谱、气相色谱和核磁共振波对SMP-4进行结构表征,并以RAW264.7巨噬细胞为模型,通过测定其细胞增殖活性和细胞因子分泌水平来评价其免疫活性。多糖结构分析表明,SMP-4是由阿拉伯糖、半乳糖、鼠李糖、核糖、木糖、葡萄糖和甘露糖组成的,摩尔比例为:0.55:0.23:0.16:0.03:0.02:0.01:0.01,分子量为1.32×10^(5) u的多糖。SMP-4具有六种糖苷键,其中→3)-D-Araf-(1→占比最高,为58.35%。在免疫活性评价分析中表明,与对照组相比,在15.625~500.000μg/mL质量浓度范围内不影响RAW264.7细胞的增殖,同时能显著地促进肿瘤坏死因子-α(TNF-α)和白细胞介素-1β(IL-1β)的分泌。SMP-4质量浓度为500μg/mL时,RAW264.7细胞分泌的TNF-α质量浓度最高,为2100.00 pg/mL(P<0.001);在31.25μg/mL质量浓度下,RAW264.7细胞分泌的IL-1β质量浓度最高,为14.50 pg/mL(P<0.05)。综上,SMP-4表现出良好免疫活性,具有成为一种天然的免疫调节剂的潜力。展开更多
As an alternative to conventional energy conversion and storage reactions,gas-involved electrochemical reactions,including the carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and hydrogen e...As an alternative to conventional energy conversion and storage reactions,gas-involved electrochemical reactions,including the carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and hydrogen evolution reaction(HER),have become an emerging research direction and have gained increasing attention due to their advantages of environmental friendliness and sustainability.Various studies have been designed to accelerate sluggish kinetics but with limited results.Most of them promote the reaction by modulating the intrinsic properties of the catalyst,ignoring the synergistic effect of the reaction as a whole.Due to the introduction of gas,traditional liquid-solid two-phase reactions are no longer applicable to future research.Since gas-involved electrochemical reactions mostly occur at the junctions of gaseous reactants,liquid electrolytes and solid catalysts,the focus of future research on reaction kinetics should gradually shift to three-phase reaction interfaces.In this review,we briefly introduce the formation and constraints of the three-phase interface and propose three criteria to judge its merit,namely,the active site,mass diffusion and electron mass transfer.Subsequently,a series of modulation methods and relevant works are discussed in detail from the three improvement directions of‘exposing more active sites,promoting mass diffusion and accelerating electron transfer’.Definitively,we provide farsighted insights into the understanding and research of three-phase interfaces in the future and point out the possible development direction of future regulatory methods,hoping that this review can broaden the future applications of the three-phase interface,including but not limited to gas-involved electrochemical reactions.展开更多
Substantial progress has been made in the understanding of gas-involving electrochemical reactions recently for the sake of clean,renewable,and efficient energy technologies.However,the specific influence mechanism of...Substantial progress has been made in the understanding of gas-involving electrochemical reactions recently for the sake of clean,renewable,and efficient energy technologies.However,the specific influence mechanism of the microenvironment at the reaction interface on the electrocatalytic performance(activity,selectivity,and durability)remains unclear.Here,we provide a comprehensive understanding of the interfacial microenvironment of gas-involving electrocatalysis,including carbon dioxide reduction reaction and nitrogen reduction reaction,and classify the factors affecting the reaction thermodynamics and kinetics into gas diffusion,proton supply,and electron transfer.This categorization allows a systematic survey of the literature focusing on electrolyzer-level(optimization of the device,control of the experimental condition,and design of the working electrode),electrolytelevel(increase of gas solubility,regulation of proton supply,and substitution of anodic reaction),and electrocatalyst-level strategies(promotion of gas affinity,adjustment of hydrophobicity,and enhancement of conductivity),aiming to retrieve the correlations between the microenvironment and electrochemical performance.Finally,priorities for future studies are suggested to support the comprehensive improvement of next-generation gas-involving electrochemical reactions.展开更多
基金supported by the National Natural Science Foundation of China[Nos.U21A20332,52103226,52202275,52203314,and 12204253]the Distinguished Young Scholars Fund of Jiangsu Province[No.BK20220061]the Fellowship of China Postdoctoral Science Foundation[No.2021M702382]。
文摘Ammonia(NH_(3))is a multifunctional compound that is an important feedstock for the agricultural and pharmaceutical industries and attractive energy storage medium.At present,NH_(3)synthesis is highly dependent on the conventional Haber–Bosch process that operates under harsh conditions,which consumes large quantities of fossil fuels and releases a large amount of carbon dioxide.As an alternative,electrosynthesis is a prospective method for producing NH_(3)under normal temperature and pressure conditions.Although electrocatalytic nitrogen reduction to ammonia has attracted considerable attentions,the low solubility of N_(2)and high N≡N cracking energy render the achievements of high NH_(3) yield rate and Faradaic efficiency difficult.Nitrate and nitrite(NO_(x)^(-))are common N-containing pollutants.Due to their high solubilities and low dissociation energy of N=O,NO_(x)^(-)−are ideal raw materials for NH_(3) production.Therefore,electrocatalytic NO_(x)^(-)−reduction to NH_(3)(eNO_(x)RR)is a prospective strategy to simultaneously realise environmental protection and NH_(3) synthesis.This review offers a comprehensive understanding of the thriving eNO_(x)RR under ambient conditions.At first,the popular theory and mechanism of eNO_(x)RR and a summary of the measurement system and evaluation criteria are introduced.Thereafter,various strategies for developing NO_(x)−reduction catalysts are systematically presented and discussed.Finally,the challenges and possible prospects of electrocatalytic NO_(x)^(-1) reduction are outlined to facilitate energy-saving and environmentally friendly large-scale synthesis of NH_(3) in the future.
基金supported by the Science and Technology Development Fund of Macao SAR(FDCT0128/2022/A,0020/2023/RIB1,0111/2023/AFJ,005/2022/ALC)the Shandong Natural Science Foundation of China(ZR2020MA004)+2 种基金the National Natural Science Foundation of China(12071272)the MYRG 2018-00168-FSTZhejiang Provincial Natural Science Foundation of China(LQ23A010014).
文摘This study introduces a pre-orthogonal adaptive Fourier decomposition(POAFD)to obtain approximations and numerical solutions to the fractional Laplacian initial value problem and the extension problem of Caffarelli and Silvestre(generalized Poisson equation).As a first step,the method expands the initial data function into a sparse series of the fundamental solutions with fast convergence,and,as a second step,makes use of the semigroup or the reproducing kernel property of each of the expanding entries.Experiments show the effectiveness and efficiency of the proposed series solutions.
基金supported by the National Natural Science Foundation of China(U21A20332,52103226,52202275,52203314,and 12204253)the Distinguished Young Scholars Fund of Jiangsu Province(BK20220061)the Fellowship of China Postdoctoral Science Foundation(2021 M702382)。
文摘As an alternative to conventional energy conversion and storage reactions,gas-involved electrochemical reactions,including the carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and hydrogen evolution reaction(HER),have become an emerging research direction and have gained increasing attention due to their advantages of environmental friendliness and sustainability.Various studies have been designed to accelerate sluggish kinetics but with limited results.Most of them promote the reaction by modulating the intrinsic properties of the catalyst,ignoring the synergistic effect of the reaction as a whole.Due to the introduction of gas,traditional liquid-solid two-phase reactions are no longer applicable to future research.Since gas-involved electrochemical reactions mostly occur at the junctions of gaseous reactants,liquid electrolytes and solid catalysts,the focus of future research on reaction kinetics should gradually shift to three-phase reaction interfaces.In this review,we briefly introduce the formation and constraints of the three-phase interface and propose three criteria to judge its merit,namely,the active site,mass diffusion and electron mass transfer.Subsequently,a series of modulation methods and relevant works are discussed in detail from the three improvement directions of‘exposing more active sites,promoting mass diffusion and accelerating electron transfer’.Definitively,we provide farsighted insights into the understanding and research of three-phase interfaces in the future and point out the possible development direction of future regulatory methods,hoping that this review can broaden the future applications of the three-phase interface,including but not limited to gas-involved electrochemical reactions.
基金National Natural Science Foundationof China,Grant/Award Numbers:U21A20332,52103226,52071226Outstanding Youth Foundation of Jiangsu Province,Grant/Award Number:BK20220061+2 种基金Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20201171Key Research and Development Plan of Jiangsu Province,Grant/Award Number:BE2020003-3Fellowship of China Postdoctoral Science Foundation,Grant/Award Number:2021M702382。
文摘Substantial progress has been made in the understanding of gas-involving electrochemical reactions recently for the sake of clean,renewable,and efficient energy technologies.However,the specific influence mechanism of the microenvironment at the reaction interface on the electrocatalytic performance(activity,selectivity,and durability)remains unclear.Here,we provide a comprehensive understanding of the interfacial microenvironment of gas-involving electrocatalysis,including carbon dioxide reduction reaction and nitrogen reduction reaction,and classify the factors affecting the reaction thermodynamics and kinetics into gas diffusion,proton supply,and electron transfer.This categorization allows a systematic survey of the literature focusing on electrolyzer-level(optimization of the device,control of the experimental condition,and design of the working electrode),electrolytelevel(increase of gas solubility,regulation of proton supply,and substitution of anodic reaction),and electrocatalyst-level strategies(promotion of gas affinity,adjustment of hydrophobicity,and enhancement of conductivity),aiming to retrieve the correlations between the microenvironment and electrochemical performance.Finally,priorities for future studies are suggested to support the comprehensive improvement of next-generation gas-involving electrochemical reactions.