壳聚糖包覆多孔碳骨架的可控制备及其电催化性能

燃料电池是一种环境友好、转换效率高、能量密度高的能量转换装置，可将化学能直接转换为电能。但目前应用于阴极氧还原（oxygen reduction reaction, ORR）的铂基催化剂价格昂贵、资源稀缺、抗甲醇能力低的缺点限制了它的应用。基于此，以生物质材料壳聚糖为前驱体，通过水热法将壳聚糖包覆到分层多孔氮掺杂碳骨架（hierarchically porous nitrogen-doped carbon, HPC）上，经高温处理得到了高效的铁掺杂壳聚糖包覆HPC催化剂（Fe-HPC@CTS）。研究结果表明：壳聚糖已包覆到HPC上，有效的提升了催化剂的比表面积；壳聚糖包覆HPC，一方面增加了催化剂中的活性位点，另一方面HPC提供了导电性好、比表面积大的基底，从而使得催化剂拥有一个良好的电子传输通道以及暴露更多的活性位点，从而使催化剂的ORR性能有明显的提升；该催化剂在碱性条件下ORR半波电位为0.80 V，极限电流密度为6.50 mA·cm^-2。通过抗甲醇性能测试，该催化剂的抗甲醇性能要优于20% Pt/C催化剂。

Controllable Preparation and Electrocatalytic Properties of Chitosan Coated Porous Carbon Skeleton

Fuel cell is an environmentally friendly, high conversion efficiency and high energy density energy conversion device that can directly convert chemical energy into electrical energy. However, the platinum-based catalysts currently used in the oxygen reduction reaction (ORR), have some disadvantages including high price, scarce resources and low methanol resistance, which limit their applications. Based on this, using chitosan as biomass precursor, hierarchically porous nitrogen-doped carbon (HPC) was coated with chitosan by hydrothermal method, and the iron-doped chitosan coated HPC catalyst was obtained after high temperature treatment. The research results show that chitosan has been coated on HPC, which effectively increases the specific surface area of the catalyst. And the ORR performance of the catalyst has been significantly improved, which is attributed to the chitosan-coated HPC. On the one hand, the active sites in the catalyst are increased. On the other hand, HPC provides a substrate with good conductivity and large specific surface area, so that the catalyst has a good electron transport channel and exposes more active sites. The ORR half-wave potential of the catalyst is 0.80 V and the limiting current density is 6.50 mA·cm⁻² under alkaline conditions. The catalyst shows better methanol resistance than 20% Pt/C catalyst through methanol resistance test.