钴酞菁/多孔碳气凝胶复合结构用于高效电催化CO_(2)还原

Cobalt phthalocyanine/porous carbon aerogel composite for efficient electrocatalytic CO_(2)reduction

利用可再生能源将CO_(2)转化成高附加值的燃料或化学品,是一项实现“碳中和,碳达峰”的新资源化技术,但目前高性能电催化CO_(2)转化的催化剂研发,仍然是一项热点问题。设计具有“类珊瑚状”结构的多级孔氮掺杂碳气凝胶(N-CA)作为优化气体传质的碳载体,利用非共价固定技术,将酞菁钴(CoPc)稳定于气凝胶骨架的表面,以实现活性位点和导电碳骨架稳定结合。CoPc@N-CA展现出优异的电催化CO_(2)还原(CO_(2)RR)活性,在较宽的电势窗口-0.5~-1.0 V vs.RHE下,对CO的选择性>80%,最高为99.05%;在-0.85 V vs.RHE电位下,CoPc@N-CA对CO的部分电流密度达到14.40 mA·cm^(-2),约是以商业碳黑(CB)为基底设计的CoPc@CB(3.66·mA cm^(-2))催化剂的4倍。内在活性分析发现,CoPc@N-CA优异的活性可归因于N-CA独特的多孔结构,这不仅促进了CO_(2)分子的传质,有利于CO_(2)RR反应动力学,而且有利于暴露Co活性位点,从而促进CO_(2)RR。

Electrocatalytic CO_(2)reduction into high value-added fuels or chemicals by renewable energy to achieve the“carbon neutrality and peak”is attractive,but still challenged by developing high-performance electrocatalytic catalysts for electrocatalytic CO_(2)reduction reaction(CO_(2)RR).Herein,porous nitrogen-doped carbon aerogels(N-CA)with“coral-like”structure was designed as the substrate to optimize gas mass transfer,and cobalt phthalocyanine(CoPc)was stabilized on N-CA surface by non-covalent immobilization technology to obtain CoPc@N-CA,realizing the stable combination of active sites and conductive carbon skeleton.As a result,CoPc@N-CA exhibits excellent CO_(2)RR activity,CO Faradaic efficiency(FECO)80%at the wide potential window of-0.5 to-1.0 V vs.RHE,and the maximal FECO of 99.05%.Meanwhile,CoPc@N-CA reaches a high CO partial current density(jCO)of 14.40 mA·cm^(-2)at-0.85 V vs.RHE,which is close to 4 times of that of CoPc@CB(3.66 mA·cm^(-2)),where carbon black(CB)was chosen as substrate to obtain CoPc@CB.Intrinsic activity analysis illustrates that the excellent activity of CoPc@N-CA can be attributed to the unique porous structure of N-CA,which not only promotes the mass transfer of CO_(2)molecules,but also facilitates the reaction kinetics of CO_(2)RR,and exposes the active sites of Co,promoting the activity CO_(2)RR.