生物质转化制备高性能环境能源碳材料的基础研究

Biomass is one of the most abundant renewable resources on planet. In China, just the agricultural activity alone annually produces over 700 million tons of straw-based biomasses. Other than small portion being effectively utilized, the vast majority of such agricultural by-products are consumed via burning or natural degradation, which not only wastes valuable resources but also causes serious environmental pollution due to the huge amount of green-house gases generated during the burning and natural degradation processes. Therefore, the development of enabling technologies to convert/transform biomass into valuable functional materials is not only benefit the environment but also critically important for sustainable development. This project aims to tackle such an important issue by developing new methods capable of transforming straw type of raw biomasses into valuable high performance carbon-based functional materials. The straw type of biomasses possesses unique features of relatively fixed chemical composition and structure at molecular level, highly ordered structural arrangement at macro-scale and rich in N and S. The new methods are designed to utilize these unique features to their full advantages, though controllable carbonisation, functionalization and structural construction processes to fabricate the trimodal-porous (Micro-, Meso- and Macro-) structured 3D graphitic carbon network. The materials will be purposely designed and synthesized with the desirable functionalities and porous structures to suit the needs for high performance carbon-based electrocatalysts for oxygen reduction reaction (ORR) and ion-uptake electrode materials for capacitive deionisation (CDI) desalination. The success of the proposed project will serve the needs of electrocatalysts with high performance, plentiful and low cost properties for large-scale fuel-cell production, and for developing the high efficiency CDI desalination technology with low energy consumption electrode materials. The success of the project will also enrich the knowledge related to biomass transformation, functionalization, structure design and construction, providing sound scientific and technological foundations to enable the wide-spread use of biomass products for energy and environmental applications...

生物质是地球上最丰富的可再生资源之一，仅农作物秸秆一项中国每年的产量就超过7亿吨，很少被有效利用，其余全部被焚烧或经自然降解而被消耗，造成巨大资源浪费和对环境的严重污染。因此，作物秸秆的有效利用对改善环境和可持续发展具有双重意义。本项目针对上述重要需求，利用秸秆类生物质具有分子水平上的固定化学结构组成、宏观尺度上天然的有序材料结构及富含氮、硫元素的优势，通过碳化转化及功能化修饰，构筑具有微、介、大孔结构的三维碳材料，并研究其相关基础科学问题，最终制备高性能、低成本的碳基电化学催化剂及低能耗碳基离子去除电极材料，为解决限制燃料电池大规模生产应用和发展电容去离子海水淡化技术中的瓶颈问题提供技术支持。本项目的实施将增进对生物质转化、功能化及结构设计中基础科学问题的理解，同时为促进生物质高端利用技术的发展和生物质材料在能源、环境领域的普及应用奠定基础。

发展廉价、高效的碳基氧还原反应电催化剂及离子去除电极材料是燃料电池和电容去离子海水淡化技术大规模生产应用的关键。迄今为止，这些碳基材料几乎都是由化石燃料转化的化学品制备获得，无疑提高了实际使用的成本。生物质是地球上最丰富的可再生资源之一，例如农作物秸秆除很少被有效利用外，其余全部被焚烧或经自然降解而被消耗，造成巨大资源浪费和对环境的严重污染。秸秆类生物质具有分子水平上的固定化学结构组成、宏观尺度上天然有序材料结构及富含氮、硫元素的优势，通过碳化转化及功能化修饰，是制备高性能、低成本碳基电化学催化剂及低能耗碳基离子去除电极材料理想原料。为此，本项目的研究内容主要包括：（1）利用丰富、廉价、可再生的作物秸秆等为原材料，发展简捷、有效的转化方法制备用于能源及环境领域的高性能碳材料，并针对生物质转化过程中的基础科学问题展开研究；（2）生物质转化制备碳材料的微观、介观及宏观结构设计、构筑及功能化研究；（3）有针对性地制备高性能生物质碳基氧还原反应电催化剂及电容去离子电极材料，系统地评价材料的应用性能，并揭示材料组成、结构等与其性能的内在关联性。围绕上述研究内容，本项目获得了一系列廉价、高效生物质碳基电催化剂材料，展示出优异的氧还原反应活性，而且在电催化分解水产氢、产氧及氮还原产氨应用中也表现出巨大潜势；发展的离子去除生物质碳基电极材料，不仅展现出优异的电容除盐性能，为电容去离子海水淡化技术的实际应用提供了技术支持，还可选择性去除水体中重金属离子及砷、氟等污染物。在上述研究基础上，研制了实验室尺度电容去离子净水装备。依托本项目总计发表SCI检索论文69篇，申请国家发明专利17项，并获授权专利7项，完成项目所有既定目标。本项目的成功完成，增进了对生物质转化、功能化及结构设计中基础科学问题的理解，同时为生物质高端利用技术的发展和生物质材料在能源、环境领域的普及应用奠定了坚实基础。