Hybrid Layered Double Hydroxides for CO2 Conversion to Useful Chemicals

大气中的二氧化碳（CO2）水平已经上升到超过400 ppm，这是人类活动的结果，包括提取和燃烧化石燃料作为能源，以及在日常生活中制造一系列产品。为了过渡到净零并将温度上升控制在巴黎协定的1.5摄氏度目标之下，提出了两种方法-通过可再生能源减少排放，以及从大气中去除二氧化碳。从大气中去除后，CO2可以储存或用作化学合成的原料，例如用于聚合物或甲醇。90年代的奥拉。甲醇是最简单的酒精，仅由一个碳原子组成，可用作清洁燃料，仅排放二氧化碳和水，与化石燃料燃烧相比，其他有毒气体或烟尘的量要少得多。目前，甲醇是由合成气生产的，合成气是通过在金属催化剂上在相对高的温度和压力下重整天然气而产生的。然而，目前正在寻求替代的、更可持续的方法。如果甲醇可以从捕获的二氧化碳和可再生的氢气中合成，整个过程就变成了碳中性。此外，甲醇是化学工业生产一系列更复杂分子的有用原料，也用作溶剂。2018年全球甲醇产量达到8500万吨，足以每12分钟填满一个奥运会游泳池。层状双氢氧化物（LDHs）是一类离子固体，其结构基于天然矿物水滑石。它们由带正电荷的层制成，这允许一系列带负电荷的离子插入层间空间。改变层状结构中的元素和可以插入其间的化学物质的能力意味着它们的性质可以由研究人员针对特定应用进行定制。这些可以从吸附到塑料添加剂到药物输送载体。LDHs也可以用作催化剂，加速化学反应的材料，或使其首先发生。最近，LDH已被用于催化氢气与二氧化碳的加成，产生甲醇，然而具有低的总产率。该项目旨在合成更多的LDH材料，其中包含不同的金属，将用于二氧化碳催化加氢生产甲醇的测试。与该领域以前的工作相比，这些工作的目标是提高CO2转化率和选择性，从而提高总的甲醇产率。该项目属于EPSRC制造未来和物理科学主题的福尔斯。

Carbon dioxide (CO2) levels in the atmosphere have risen to over 400 ppm, as a result of human activities including the extraction and burning of fossil fuels for energy, and in the manufacture of a range of products in everyday life. In order to transition to net zero and keep temperature rises below the 1.5oC target of the Paris Agreement, two approaches are proposed - reduction in emissions through renewable sources of energy, and removal of CO2 from the atmosphere. Upon removal from the atmosphere, CO2 can be stored or used as a feedstock in chemical synthesis, for example for polymers or methanol.The concept of the methanol economy was proposed by George A. Olah in the 1990s. Methanol is the simplest alcohol, composed of only one carbon atom, and can be used as a clean fuel, emitting only CO2 and water, and much smaller amounts of other toxic gases or soot compared to the combustion of fossil fuels. Methanol is currently produced from syngas, generated by reforming natural gas, over a metal catalyst at relatively high temperatures and pressures. However, alternative, more sustainable methods are currently being pursued. If methanol can be synthesised from captured CO2 and renewable hydrogen, this whole process becomes carbon neutral. In addition, methanol is a useful feedstock to the chemical industry to produce a range of more complex molecules, and is also used as a solvent. This is reflected in the global production of methanol, which reached 85 million tonnes in 2018, enough to fill an Olympic swimming pool every twelve minutes.Layered double hydroxides (LDHs) are a class of ionic solid with a structure based on that of the naturally occurring mineral hydrotalcite. They are made of positively charged layers, which allows a range of negatively charged ions to be inserted in the interlayer space. The ability to vary the elements in the layered structure and the chemicals that can be inserted between means their properties can be tailored by researchers towards specific applications. These can range from adsorption to plastic additives to vehicles for drug delivery.LDHs are also able to be used as catalysts, materials which speed up a chemical reaction, or enable it to occur in the first place. Recently, LDHs have been used to catalyse the addition of hydrogen gas to carbon dioxide, producing methanol, however with low overall yield. This project aims to synthesise more LDH materials incorporating different metals, which will be tested for the catalytic hydrogenation of carbon dioxide to produce methanol. Compared to previous work in this area, these will aim to have improved CO2 conversion and selectivity, and therefore increased overall methanol yield.This project falls within the EPSRC manufacturing the future and physical sciences themes.