Squeezing hydrogen out of biomass; new catalysts for clean energy generation.

氢气是用于发电的燃料电池的理想试剂，因为其燃烧产生的唯一产物是水。然而，来自不可再生资源的氢气与任何其他化石燃料一样存在同样的缺点。相比之下，由生物质产生的氢代表了碳中性来源，因此是一个更有吸引力的替代品。生物质含有丰富的复杂分子物质，其中富含醇的物质具有很高的代表性。通常以碳水化合物为基础，包括淀粉和较小的低聚糖，以及较小的分子，如甘油。氢化酶能从醇类（包括碳水化合物）中释放氢，但对底物有高度的特异性，因此不能从给定的底物中释放所有可用的氢。近年来已报道了用于同一过程的化学催化剂，但数量少，活性不高，尽管它们受益于广泛的底物范围。在这方面，从富含碳水化合物的生物质中产生氢的化学催化剂为清洁燃料电池的运行提供了巨大的潜力。在华威大学正在进行的研究过程中，已经确定了一些用于从甲酸中生成氢的有机金属催化剂，其中一些表现出翻转频率(测量为no。每个催化剂分子每小时产生1万个氢，这对于化学催化剂来说是非常高的。考虑到甲酸脱氢机理与醇脱氢机理之间的密切关系，可以预期这些催化剂也能从醇中生成氢。本提案的工作目标是将新的有机金属配合物应用于从生物质中产生氢气，最重要的是，碳水化合物和甘油。为了优化这一过程，我们将研究一些旨在提高稳定性和活性的催化剂改性。该项目将采用综合方法，将氢发电与燃料电池发电结合起来。该项目的这一部分将在伯明翰大学进行，在燃料电池制造和使用方面的权威机构的监督下进行。产氢过程的副产物应被表征并转化为进一步的有价值的产品或进一步的氢等价物。到项目结束时，我们的目标是生产出一种强大而活跃的催化剂，用于生物质制氢，并证明其通过与燃料电池耦合进一步发电的能力。这项可行性研究将成为进一步向工业和研究理事会申请扩大项目发展资金的基础。

Hydrogen gas represents a desirable reagent for the use in fuel cells for electricity generation because the only production of its combustion is water. Hydrogen gas from non-renewable sources, however, suffers from the same shortcomings as any other fossil fuel. In contrast, hydrogen generated from biomass represents a carbon neutral source, and therefore a much more attractive alternative.Biomass contains a rich array of complex molecular materials, of which alcohol rich material is highly represented. Must commonly this is carbohydrate based and includes starch and smaller oligosaccharides, as well as smaller molecules such as glycerol. Hydrogenase enzymes achieve the release of hydrogen from alcohols, including carbohydrates, but are highly substrate specific and therefore unable to release all the available hydrogen from a given substate. Chemical catalysts for the same process have been reported in recent years, but are small in number and not of high activity, although they benefit from a wide substrate scope. In this regard, chemical catalysts for hydrogen generation from carbohydrate-rich biomass offer significant potential for clean fuel cell operation.In the course of ongoing studies at Warwick, a number of organometalluc catalysts for the generation of hydrogen from formic acid have been identified, some of which exibit turn over frequencies (measured as no. molecules hydrogen produced by each molecule of catalyst per hour) of some 10,000, which is unusually high for a chemical catalyst. Given the close relationship between the mechanism of formic acid dehydrogenation and that of alcohol dehydrogenation, it is would be expected that these catalysts are also capable of hydrogen generation from alcohols. The objective of the work in this proposal is to apply new organometallic complexes to the generation of hydrogen gas from biomass and, most significantly, carbohydrates and glycerol. In order to optimise this process, a number of catalyst modifications, designed to improve stability and activity will be examined. The project will take an intergrated approach to the coupling of hydrogen generation to electricity generation using fuel cells. This part of the project will be conducted at Birmingham University, under the supervision of an authority in the fabrication and use of fuel cells. The side products from the hydrogen generation process shall be characterised and converted into further products of value or to further equivalents of hydrogen.By the end of the project, we aim to have produced a robust and active catalyst for hydrogen generation from biomass, and have demonstrated its ability to further generation electricity through coupling to fuel cells. This feasibility study will form the basis of further applications for extended funding of the development of the project from industry and research councils.