Earth-Abundant Transition Metal Catalysts for HX Splitting

地球上储量丰富的用于 HX 裂解的过渡金属催化剂

• 批准号: 8398128
• 负责人: David C Powers
• 金额: $ 2.16万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-06 至 2013-01-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8398128
• 关键词: Acids; Air Pollution; Anions; Automobile Exhaust; Carbon Dioxide; Catalysis; Cells; Cessation of life; Charge; Chemicals; Chemistry; Complex; Coupled; Development; Electronics; Energy Supply; Energy-Generating Resources; Environment; Evolution; Family; Future; Goals; Health; Human; Hydrogen; Hydrogenation; Investigation; Ligands; Liquid substance; Metals; Minerals; Molecular; Nature; Particulate; Petroleum; Process; Production; Protons; Reaction; Research; Scheme; Secure; Source; System; Time; Transition Elements; base; catalyst; design; meetings; metal complex; metalloenzyme; novel; oxidation; protonation; small molecule

DESCRIPTION (provided by applicant): Identification and implementation of clean, sustainable, and affordable energy sources is of paramount importance for both environmental and human health concerns in the future. Sustainable hydrogen-based economies require that hydrogen production from protic media, such as H2O or mineral acids (HX), be coupled to solar power. Closed catalytic cycles for solar-to-hydrogen energy conversion from protic media must meet two technological hurdles: 1) proton reduction to generate dihydrogen, and 2) anion oxidation. A closed cycle for generating H2 from HX requires both proton reduction to form H2 as well as halide oxidation to generate X2. Thus far, molecular catalysts for authentic HX splitting have not been developed. Proof-of-concept systems, which employ chemical traps to promote X2 formation have been developed, however, these systems are not amenable to use in energy storage. This proposal aims to develop inexpensive catalysts based on earth- abundant, first-row transition metals for photochemical HX splitting. If successful, the proposed research would constitute a closed solar-to-hydrogen conversion scheme, in which mineral acids (HX) are converted to H2 and X2 using solar power. The resultant hydrogen could be used as fuel, either by sequestration as a liquid fuel by hydrogenation of small molecule substrates such as CO2 or by being used directly in hydrogen fuel cells. To accomplish the goal of developing a solar-to-hydrogen scheme, low-valent transition metal complexes, capable of proton reduction will first be developed. Simultaneously, investigations of metal dihalide complexes will allow critical requirements for halide oxidation to be defined. To enable the challenging, but necessary, X2 photoelimination, ligands wil be designed to provide access to highly oxidizing excited states. Studies of each of the fundamental steps of HX splitting - proton reduction and halide oxidation - will elucidate fundamental parameters required for each of the constituent half reactions. Informed by the requisite ligand features for each of the fundamental steps of HX splitting, transition metal catalysts will be designed to enable authentic HX splitting photocatalysis to be achieved. PUBLIC HEALTH RELEVANCE: Identification and implementation of clean, sustainable, and affordable energy sources is of paramount importance for both environmental and human health concerns in the future. In 2005 it was estimated that particulate air pollution, whose major source in urban environments is automobile exhaust, is to blame for 500,000 deaths each year. Herein, I propose the development of novel transition metal catalysts for HX splitting, which would enable use of non-polluting hydrogen-based fuels and sever the connection between energy and petroleum-based fuels.

描述（由申请人提供）：清洁，可持续和负担得起的能源的识别和实施对于将来的环境和人类健康问题至关重要。可持续氢的经济体要求将氢培养基（例如H2O或矿物质酸（HX））产生与太阳能耦合。来自原始培养基的太阳能到氢能转化的封闭催化循环必须符合两个技术障碍：1）质子还原以产生二氢，以及2）阴离子氧化。从HX产生H2的封闭循环需要还需要还原质子以形成H2以及卤化物氧化以产生X2。到目前为止，尚未开发用于正宗HX分裂的分子催化剂。已经开发了采用化学陷阱来促进X2形成的概念验证系统，但是，这些系统不适合用于储能。该提案旨在基于地球丰富的第一行过渡金属来开发廉价的催化剂，用于光化学HX分裂。如果成功，则提出的研究将构成一种封闭的太阳能到氢转化方案，其中矿物酸（HX）使用太阳能转化为H2和X2。所得的氢可以通过固换作为液体燃料来将其用作燃料，这是通过小分子底物（例如CO2）的氢化，或直接在氢燃料电池中使用。为了实现开发太阳能到氢化方案的目标，将首先开发能够减少质子的低价过渡金属配合物。同时，对金属二甲化合物配合物的研究将允许定义卤化物氧化的关键要求。为了使具有挑战性但必要的X2光照明，将设计配体旨在提供高度氧化激发态的访问。对HX分裂的每个基本步骤的研究 - 质子还原和卤化物氧化 - 将阐明每个组成部分反应所需的基本参数。由HX分裂的每个基本步骤所必需的配体特征所告知，将设计过渡金属催化剂，以实现真实的HX分裂 要实现的光催化。 公共卫生相关性：识别和实施清洁，可持续和负担得起的能源对于将来的环境和人类健康问题至关重要。据估计，在城市环境中的主要来源是汽车排气的颗粒物空气污染，每年应归咎于500,000人死亡。本文中，我提出了用于HX分裂的新型过渡金属催化剂的开发，该催化剂可以使用非污染氢的燃料，并切断能量与基于石油的燃料之间的联系。