Hydrogen-free hydrogenolysis of strong C-S, C-O, and C-N bonds

强 C-S、C-O 和 C-N 键的无氢氢解

• 批准号: RGPIN-2022-03282
• 负责人: Stryker, Jeffrey
• 金额: $ 3.5万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748113
• 关键词: Hydrogen; free; hydrogenolysis; strong; bonds

This proposal reflects fundamental discovery and development research directed toward mitigating two significant impediments to a sustainable modern economy: heavy petroleum utilization and renewable biomass "valourization" specifically targeting waste wood and agricultural lignin. We seek disruptive innovation in both industries, one moribund, one emergent. Bitumen refining is capital- and energy-intensive, consuming hydrogen at very high temperatures and pressures. The highest molecular weight fraction of bitumen, the asphaltenes, contain most of the refractory sulfur, nitrogen, and metal compounds in heavy oil. Asphaltenes are barely soluble in the petroleum matrix, fouling pipelines and refineries. Removing heteroatoms and metals from heavy oil is currently accomplished by pyrolytic coking, destroying ~20-30% of the hydrocarbon value in bitumen to convert the remainder into fuels and petrochemicals. Petroleum coke is toxic, valueless, environmentally persistent, and produced on unimaginable scale. The inefficiency of this process is unsustainable, but alternative de-asphalting methods are rudimentary and more expensive than coking. No "techno-economic" new methods or technologies have emerged have appeared in decades. Under NSERC support, we have discovered two radically new, obstacle-free, and inexpensive pathways to hydrogen-free hydrodesulfurization of the asphaltenes and native lignin: reductive electrocatalysis and heterogeneous hydrogen-transfer catalysts under (very) mild conditions. Electrocatalytic upgrading of bitumen asphaltenes recently crossed from discovery science to process development;  funding from other sources is now used for that purpose. In this proposal, however, we propose to investigate novel catalyst design and synthetic and supramolecular modelling of asphaltene structures and aggregation, about which little is known.         Lignin is the oxygenated polymer that gives woody biomass its structure and strength. Forestry and agricultural waste-woods have no economic value in today's market: pyrolytic gasification is regressive and energetically counterproductive. No non-destructive processes for lignin depolymerization have been reported - until now. Heterogeneous copper catalysts for hydrogen-free depolymerization and deoxygenation of lignin and model compounds have been demonstrated, albeit not optimized.  The nanocatalysts function by hydrogen-transfer hydrogenolysis, stripping hydrogen from a neighbouring alcohol and it using to cleave the carbon-oxygen bond that holds the polymer together. The products are simple aromatic alcohols. No complex bio-oils or gases. Electrocatalytic depolymerization/deoxygenation of lignin remains at the discovery stage, and provides another of this proposal.   Inorganic and organic synthesis, heterogeneous catalysis, reaction mechanisms, supramolecular chemistry, and computational theory:  discovery research witin the constraints of industrial reality.

这一提议反映了旨在减少可持续现代经济的两个重大障碍的基础发现和开发研究：重石油利用和可再生生物质“有价化”，特别是针对废木材和农业木质素。我们在两个行业都寻求颠覆性创新，一个是垂死的，一个是新兴的。沥青精炼是资本和能源密集型的，在非常高的温度和压力下消耗氢气。沥青中相对分子质量最高的部分，即沥青质，含有重油中大部分难熔的硫、氮和金属化合物。沥青质几乎不溶于石油基质，污染了管道和炼油厂。目前，从重油中去除杂原子和金属的方法是通过热解焦化，破坏沥青中约20%-30%的碳氢化合物价值，将剩余的转化为燃料和石化产品。石油焦有毒，没有价值，对环境具有持久性，并且生产规模难以想象。这一过程的低效是不可持续的，但替代的脱沥青方法是初级的，而且比焦化更昂贵。几十年来，没有出现过任何“技术经济”的新方法或新技术。在NSERC的支持下，我们发现了两种全新的、无障碍的、廉价的方法来实现沥青质和天然木质素的无氢加氢脱硫：还原电催化和非均相氢转移催化剂。沥青沥青质的电催化升级最近从发现科学跨越到工艺开发；来自其他来源的资金现在用于这一目的。然而，在这项建议中，我们建议研究新的催化剂设计以及沥青质结构和聚集的合成和超分子模拟，这些都是鲜为人知的。木质素是一种含氧聚合物，赋予木质生物质结构和强度。林业和农业废木在今天的市场上没有经济价值：热解气化是倒退的，而且会适得其反。到目前为止，还没有关于木质素解聚的非破坏性方法的报道。用于木质素和模型化合物无氢解聚和脱氧的多相铜催化剂已经被证明，尽管还没有得到优化。纳米催化剂通过氢转移氢解作用发挥作用，从邻近的醇中剥离氢气，并用它来裂解将聚合物结合在一起的碳氧键。产品为简单的芳香醇。没有复杂的生物油或气体。木质素的电催化解聚/脱氧仍处于发现阶段，并提供了另一种建议。无机和有机合成、多相催化、反应机理、超分子化学和计算理论：在工业现实的限制下的发现研究。