摘要：Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon *** H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)*** Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an *** element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)***,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current *** the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+)on the catalyst surface,which resulted in improved ethylene *** the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2)*** functional theory calculations indicated that the Cu^(0)/Cu^(+)interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H4 *** Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of*CO on the surface and facilitated C_(2)*** observa-tion explained the higher yield of C_(2)products at the Cu^(0)/Cu^(+)interface than that of H_(2)under rapid mass *** results of the net present value model showed that the H-cell holds

摘要：杂原子掺杂可以调节电子结构以调整中间体吸附并优化反应路径,是设计高效CO_(2)还原反应(CO_(2)RR)催化剂的有应用前景的方法.B原子是常用的掺杂剂,引入B原子可以有效打破*COOH和OCHO*中间体的吉布斯自由能线性关系,并且可以通过与CO_(2)中O原子结合来增强CO_(2)吸附能力.B掺杂碳材料、单金属和金属氧化物的研究结果表明,B原子掺杂催化剂的CO_(2)RR活性和/或选择性有明显提高,然而多数报道的单个活性位点的B掺杂催化剂仅表现出在相对狭窄的电位范围内的CO_(2)RR高性能,设计制备CO_(2)RR的宽电位高选择性催化剂仍是巨大挑战.研究表明,合金化是提供多种类的活性位点相互协调和增强催化剂固有活性,进而改善CO_(2)RR性能并调节产物分布的可行策略.引入B原子到合金中以调节电子结构,最终优化关键中间体吸附的活性位点,对于寻找具有宽电位窗口的先进催化剂具有重要意义.本文提出了一种通过B掺杂调节CuIn合金电子结构以实现宽电位高选择性的电子工程策略.所制得的B掺杂CuIn合金(CuIn(B))在–0.6 V(***)时表现出99%的CO法拉第效率(FECO),并在一个宽的阴极电化学窗口(400 m V)内保持了超过90%的较高FECO.同时,采用X射线光电子能谱(XPS)和CO_(2)吸附实验等手段研究了CuIn(B)性能提升的原因,结果表明,B原子与CuIn之间存在强烈的相互作用,改变了CuIn的电子结构.CO_(2)吸附结果表明,CuIn(B)比CuIn拥有更强的CO_(2)吸附能力,证明它具有潜在的快速CO_(2)RR反应动力学.进一步通过密度泛函理论(DFT)模拟研究了催化剂的热力学反应能量学以揭示CO_(2)RR机制,结果表明,*COOH更倾向于在CuIn(B)上形成,且*CO与CuIn(B)催化位点的结合强度最佳,更利于CO_(2)还原反应为CO,而CuIn更利于作为HER的活性位点;决速步骤是*CO中间体向CO转移,以实现高CO选择性;热力学限制电位研究表明,CuIn(B)大大提高了CO_(2)到CO转化的选择性.随后通过差分电荷密度研究也进一步证明了电荷转移过程是从CuIn位点到B位点.此外,根据d带理论,催化剂中Cu和In原子的投影态密度和d带中心(Ed)研究进一步证明了催化剂结构中的电子价态的变化,与XPS结果相符;引入B可以优化催化剂的电子结构,从而调节催化剂和中间体之间的结合能力,实现了CO_(2)RR在宽电位范围内的高活性和选择性.综上,本文对于电化学CO_(2)RR机理的基础理解和其实际应用具有促进作用.

摘要：以酪蛋白和聚乙烯醇为原料,基于正交试验设计,运用静电纺丝技术纺制纳米蛋白纤维膜。研究聚乙烯醇质量分数固定时,酪蛋白质量分数、纺丝电压和接收距离等参数对纳米纤维膜成膜性的影响。分别应用透射电镜、透气性测试、傅里叶红外光谱、X射线衍射、比表面积和孔隙率测试等手段研究纤维膜微观结构、透气性、成膜性及稳定性。结果表明:所制备的纳米纤维膜为介孔结构,具有良好的孔隙率与比表面积;酪蛋白质量分数对纤维膜为主要影响因素,接收距离和纺丝电压为次要影响因素;酪蛋白与PVA分子之间以氢键结合,随着酪蛋白质量分数提升,氢键和结晶度发生变化,结合更紧密但纤维膜无序且多晶粒排列,成膜性逐渐下降。由正交试验得出,酪蛋白质量分数为5%,纺丝电压为27 kV,接收距离为9 cm时纺制的纳米纤维膜具备良好成膜性、且微观结构均匀、稳定性好。