基于不饱和脂肪酸自供氢脱羧的纳米双金属催化体系的构建

Green and renewable oils and fats have become ideal feedstock for clean energy due to the exhaustion of fossil resources and serious greenhouse effect. Main ingredients of oils and fats are unsaturated fatty acids. Two issues are focused: low yield of long-chain alkanes (75% theory yield) from decarboxylation of unsaturated fatty acids without using H2 and solvent due to lack of self-donating H2 by dehydrogenation-aromatization, and insufficient utilization of the noble metal active sites. In this proposal, bimetallic catalysts are synthesized by the atomic layer deposition to control the metal dispersion from highly dispersed nanoscale to single atom scale. The catalyst is designed for the catalytic decomposition of oleic acid or dry reforming of alkanes to produce sufficient H2. The high yield of heptadecane would be obtained (94% theory yield) without any liquid by-products. The catalytic activity and stability of metals and supports would be enhanced with the reduction of the catalyst cost. The reaction mechanisms of self-donating hydrogenation and decarboxlylation will be studied by in-situ characterization techniques. The effects of reactant loading, catalyst loadings, reaction temperature and time on the self-donating hydrogenation and decarboxlylation will be investigated to study the reaction kinetics and establish the kinetic model. A new approach of preparation of bio-fuels from oils and fats without H2 consumption will be established.

随着化石能源储存量逐年下降，温室效应日渐严重，绿色、可再生的油脂成为制备清洁能源的理想原料。油脂中以不饱和脂肪酸为主，针对不饱和脂肪酸在无氢源无溶剂体系下脱氢芳构化自供氢不足导致脱羧得到长链烷烃产率低（理论产率75%）、金属活性位利用率不高等问题，本项目以油酸为研究对象，采用原子层沉积法制备双金属催化剂并对金属活性位进行分散度的调控（从纳米高分散到极限单原子负载），催化油酸自降解/烷烃干重整制氢提供充足氢气，在无液相副产物产生的同时自供氢脱羧高产率得到十七烷（理论产率94%），在提高贵金属催化活性的同时，保证金属和载体稳定，降低催化剂成本。采用原位表征技术探究不饱和脂肪酸自供氢脱羧的反应机理，考察物料和催化剂加量、反应温度、反应时间对自供氢脱羧反应的影响，研究其反应动力学，建立动力学模型并探究其反应规律，建立油脂零氢耗制备生物燃油的新方法。

随着化石能源储存量逐年下降，温室效应日渐严重，绿色、可再生的油脂成为制备清洁能源的理想原料。油脂中以不饱和脂肪酸为主，针对不饱和脂肪酸在无氢源无溶剂体系下脱氢芳构化自供氢不足导致脱羧得到长链烷烃产率低（理论产率75%）、金属活性位利用率不高等问题，本项目原子层沉积法制备高催化活性纳米PtNi(Pt-skin表面)负载催化剂并用于油酸无氢源无溶剂条件下自供氢脱羧制备长链烷烃，并对金属活性位进行分散度的调控（从纳米高分散到极限单原子负载）提高催化活性，在无氢气的气氛下，催化油酸自降解/烷烃干重整制氢提供充足氢气，在无液相副产物产生的同时自供氢脱羧高产率得到十七烷（产率高达91%，接近理论产率94%）；利用原位技术（FTIR和EXAFS）探究油酸无氢源无溶剂催化体系中自供氢脱羧反应机理及反应动力学，并阐明其反应机理和规律性；建立无氢源无溶剂油脂自供氢脱羧高收率制备生物燃油新方法；发表期刊论文27篇，其中一作SCI论文12篇；协助培养毕业博士生和硕士生共4名，圆满完成项目研究目标。本项目可以推进生物油脂转化为长链烷烃的技术发展，为生物燃油的高效制备提供理论依据和实验基础，推进生物燃油的工业化进程。