煤沥青衍生自掺杂碳电极多尺度结构调控与同步电催化脱硫脱硝机制

Synchronization desulfurization denitration for flue gas electrolysis was restricted by the amount of reactive oxygen species (ROS). The doping structure was key to ROS generation for metal free electrode. To save the additional doping matter, increasing the doping amount, achieving the self-doping in in situ, the synergy control from molecular doping, geometry and graphite structure was controlled by the tempering coal tar pitch. The ROS generation was enhanced by using the effective synergy from molecular doping, geometry and graphite structure, and mechanism of ROS formation catalyzed by multi-scale structure of carbon electrode was proposed, and thus indicating the mechanism of synchronization desulfurization denitration electro-catalyzed by multi-scale structure of carbon electrode. .The effective synergy from molecular doping, pore distribution and graphite degree was examined by controlling the composition and structure of coal tar pitch and ingredients, and pyrolysis conditions, such as low temperature and catalysts. As a result, the controlling mechanism of multi-scale structure for coal tar pitch electrode was suggested. The synergy control of self-doping and low temperature graphitic was achieved by using heteroaromatic compound and molecular weight distribution, improving the synergy control of self-doping and graphitic structure. The ROS formation and amount were examined by using chemical probe (DMPO) and ESR, and thus the mechanism of ROS formation strengthened by multi-scale structure for electrode was obtained. The solubility of SO2 and NO was improved by using flue gas electrolysis with pressure and ionic liquid, examining the change in sulfate and nitrate concentration, and thus revealing the mechanism of synchronization desulfurization denitration for electro-catalysis by using molecular simulation, to supply the scientific basis for desulfurization denitration technology from flue gas electrolysis.

电催化烟气同步脱硫脱硝受到活性氧数量的限制，掺杂结构是非金属电极催化活性氧产生的关键。为省去外加掺杂过程，增加掺杂量，实现原位自掺杂，项目通过调质煤沥青，实现碳电极自掺杂、几何、石墨化结构的协同调控，强化活性氧形成，解析碳电极多尺度结构催化活性氧形成机制，揭示多尺度电极电催化烟气同步脱硫脱硝机理。.通过煤沥青组成与结构调制，采用可控热解过程，实现自掺杂、孔结构、石墨化度三位一体的协同调控，揭示煤沥青基电极多尺度结构调控机制；通过芳香杂环组分和分子量分布调控，实现低温石墨化与掺杂耦合，强化自掺杂与石墨化结构协同控制；通过化学探针DMPO及ESR谱，研究活性氧形成规律，揭示电极多尺度结构催化活性氧形成机制；通过烟气加压和离子液体提高SO2、NO在电解液中的溶解度，研究硫酸根，硝酸根浓度演变规律，结合分子模拟，解析电催化烟气同步脱硫脱硝机理，为电催化烟气脱硫脱硝技术提供科学依据。

电解脱硫脱硝的核心是电化学产生活性氧生成与传递。项目为了解决活性氧数量少，寿命短、传质差，氧化效率低等问题，提高大宗碳基材料的高值化利用率，提出了利用煤沥青调质与原位自掺杂实现碳电极三位一体结构的协同调控，强化活性氧形成。碳电极的掺杂结构、石墨化结构及纳微结构是决定催化性能的关键结构，为了实现主导尺度关键结构的协同调控，项目提出通过煤沥青组成与结构调控，采用可控热解过程的研究思路。通过煤沥青中化学元素组成、组分结构，分子量分布控制，解析了自掺杂结构和多孔结构调控机制；通过热解温度和石墨化试剂，揭示催化石墨化与升温石墨化耦合关系；通过自掺杂电极多尺度结构调控，从分子尺度揭示活性氧形成机制；通过研究矿物脱硫率变化规律，解析电化学氧化脱硫动力学以及电催化脱硫机制。.通过解析碳电极催化活性氧生成机制，明确碳电荷布居结构是提高活性氧生成选择性的关键。通过程序掺杂实现了煤沥青电极界面官能团的精准合成，建立了碳电极分子尺度界面结构精准合成方法。通过合成路线设计，实现碳的高局部有序化度的提高，增加高效活性位点。结果表明，高度有序结构的碳基底和Co-Nx活性中心的协同作用实现了“尖端放电效应”，解析了活性位点作用机制以及边界层传质规律。基于活性氧生成反应机理，解析了碳电极活性和选择性的调控机制，构建了碳电极结构设计合成“字典”。结果表明，给电子基团或吸电子基团的共存会提高4电子反应选择性，而吸电子基团与给电子基团的共存则会促进活性氧生成反应（2电子反应）。通过理论结合实现，解析了分子尺度的活性氧氧化脱硫机理。结果表明，在弱氧化条件下，S-S键优先断裂，只能实现部分脱硫；而在强氧化条件下，HO·选择性地断裂 Fe-S键，实现完全脱硫。通过解析碳电极催化活性氧生成能力与掺杂结构、多孔结构、有序化度的协同调控机制，建立了电化学活性氧生成调控方法，为高级氧化提供基础理论，为电解脱硫脱硝技术提供了科学依据。