金属卟啉杂化多孔碳纳米纸的可控制备及电催化还原CO2性能

Global warming and the energy crisis are rooted in the unsustainable utilization of fossil fuels accompanied with release of greenhouse gas CO2. Renewable powers are able to reduction CO2 into useful fuels, which could not only reduce CO2 emission, but also decrease the energy shortage. Two of the most urgent problems of CO2 reduction through direct electrocatalysis method are decreasing over potential and increasing product selectivity. Realizing this, we are inspired to synthesize a new kind of electrocatalysts of metal porphyrin hybrid porous carbon nanosheets, using metal porphyrin as raw material and V2O5 as template, including the pretreatment of confined assembly, carbonization and template removal. We are supposed to study the molecule delivery, distribution and exchanging properties during the confined assembly process; the effect of reactants and products regional concentrations to the balance, velocity and the premeditated products’ selectivity in the process of carbonization. We ought to illuminate the influence of fabricating conditions to the microstructure of catalysts; ultrathin structure of few atomic layer; the electro-catalytic mechanism of mental-N-C, N-C, porous architecture and active sites at carbon edges and their synergistic effects of decreasing over potential and increasing product selectivity. We are aimed to synthesize cheap and efficient new type of CO2 electrocatalysts, develop and perfect the mechanism of electrocatalytic reduction for CO2 and supply valuable information for driving on its practical applications.

全球气候变暖和能源危机源于不可持续地使用化石燃料并伴随释放温室气体CO2。用可再生电源将CO2还原为有用的燃料，不仅可以减少CO2排放量，同时也能缓解能源短缺状况。本项目针对直接电催化还原CO2过程亟待解决的降低过电位和提高产物选择性的热点和难点，设计以金属卟啉为原料，层状V2O5为模板，通过限域组装、而后碳化再去模板，制备金属卟啉杂化多孔碳纳米纸电催化新材料。研究限域组装过程中分子传递、分布和交换性能；研究碳化过程反应物和产物局部浓度对平衡、速率和预设产物选择性的影响；阐明制备条件对金属卟啉杂化多孔碳纳米纸微观结构的控制作用，阐明几个原子层的超薄结构，以及金属-氮-碳、氮-碳、多孔结构和碳边缘活性位对CO2电催化还原机理及在降低过电位和提高产物选择性方面的协同作用。得到价廉且性优的新型CO2电催化材料，发展和完善CO2电还原作用机制，为推进CO2电催化还原实用化提供有价值的设计信息。

全球气候变暖和能源危机源于不可持续地使用化石燃料并伴随释放温室气体CO2。用可再生电源将CO2还原为有用的燃料，不仅可以减少CO2排放量，同时也能缓解能源短缺状况，极具研究价值。本项目针对直接电催化还原CO2过程亟待解决的降低过电位和提高产物选择性的热点和难点，设计了以金属卟啉为原料，层状V2O5为模板，通过限域组装、而后碳化再去模板，制备金属卟啉杂化多孔碳纳米纸电催化新材料。探讨了在模板限域的反应条件下，制备原子级分散的Fe和N共掺杂碳纳米纸优化工艺参数；建立了金属单原子负载N掺杂碳纳米纸电催化材料的结构模型，采用密度泛函理论（DFT）计算了它们在CO2电还原过程中各中间态产物的吉布斯自由能，从理论上分析研究了电催化活性及产CO的选择性；研究了转化频率（TOF）、CO选择性和法拉第效率，探讨了CO2电还原机理。重点研究了Fe-N配位对电催化CO2的影响，比较了轴向Fe-N配位与平面Fe-N配位CO2还原产物CO从吸附位点解吸所需的吉布斯自由能，解释了轴向Fe-N配位对抑制析氢反应的发生、提高CO2-CO的选择性机制。.此外，还探讨了CdS纳米棒表面硫缺陷Sv和表面负载Ag2S纳米点对电还原CO2的影响。实现了表面Sv精确地连续可变。探讨了CdS纳米棒表面Sv含量和Ag2S含量对电催化CO2-CO还原反应的选择性和活性。进一步筛选了不同的过渡金属M以及其与含氮的碳复合，制备了M-N-C杂化材料。考察了氧还原反应（ORR）、氧析出反应（OER）和氢析出反应（HER）的电催化性能，评估了在水分解和金属-空气电池方面的应用，并与商用催化剂对比，阐明了作用机制。.项目在Appl. Catal. B Environ.等期刊发表标注有本课题资助的学术论文34篇（其中ESI高被引论文1篇），被SCI他引600余次。引用期刊包括Chem. Rev.、Chem. Soc. Rev.等综述性期刊以及J. Am. Chem. Soc.、Angew. Chem. Int. Ed.、Adv. Mater.等专业期刊。申请国家发明专利4项，授权1项。四年指导毕业博士生3人，毕业硕士生5人。