Exploiting Nanoparticles for Thermal and Light Driven Valorisation of Carbon Dioxide

在过去的一个世纪里，大气中二氧化碳浓度的快速上升增加了对替代燃料来源的需求，以应对气候变化。即使像英国这样的气候进步国家目前也未能达到《巴黎协定》设定的二氧化碳排放目标，1因此，开发创新技术以克服这一全球挑战的压力很大。英国政府到2050年实现净零排放的目标，部分得益于碳封存。英国最大的碳捕获工厂将于2021年投产，希望每年捕获4万吨二氧化碳-相当于2.2万辆汽车的排放量。二氧化碳的商业和工业应用相对有限，因此这些即将投入使用的捕获二氧化碳为替代燃料提供了一个令人兴奋的机会。该项目旨在开发金属纳米粒子催化剂，以促进热和光催化将二氧化碳还原为更有价值的产品，如作为储氢材料的甲酸、用作燃烧燃料的甲醇或用于生产各种精细化学品、甲烷甚至高级烷烃的氯-原料。这项工作的主要重点将是使用功能化的聚合物固定离子液体(PIIL)作为载体来稳定金纳米粒子，控制其生长(尺寸分布和形状)，改变表面电子性质，并探索是否可以利用催化剂-载体的相互作用来控制效果。PIIL载体比定制的配体更具优势，因为它们更实惠、更坚固，而且不容易淋洗，从而使催化剂能够回收和循环使用。Doherty研究小组此前发现，PIIL载体非常有利于提高金纳米粒子催化剂的活性、稳定性和对小分子还原的选择性。2报告表明，聚合物离子液体除了具有快速的二氧化碳吸附/脱附能力外，还具有很高的二氧化碳吸收能力，3因此我们打算将这项技术扩展到热和光驱动的二氧化碳还原。利用电子显微镜、X射线光电子能谱、能谱、粉末X射线衍射仪、热重分析和固体核磁共振等先进的分析技术确定催化剂的组成，用漂移、X射线光电子能谱和原位傅立叶变换红外光谱对催化剂进行表面探测和二氧化碳吸附研究。对表面-载体相互作用的详细了解将有助于深入了解影响催化剂活性和产品分布的因素，促进具有适合放大的稳定活性曲线的最佳催化剂的开发。相关EPSRC研究领域：催化、能源应用材料、碳捕获和储存、可再生能源1。安德森，K.；布罗德里克，J.F.；斯托达德，I.，《两个因素：‘气候进步’国家的缓解计划如何远远达不到符合巴黎规则的路径》。克里姆。政策2020，1-15.2。Doherty，S.；Knight，J.G.等人，在膦修饰聚合物固定离子液体稳定的AuNPs催化下，高选择性和依赖溶剂将硝基苯还原为N-苯基羟胺、偶氮苯和苯胺。卡塔。2019年、9(6)、4777-4791.3。用于二氧化碳捕获和分离的聚合物离子液体：潜力、进展和挑战。波兰姆。化学。2015年，6(36)，6435-6451。

The rapid rise in the concentration of atmospheric CO2 over the past century has increased demand for alternative fuel sources to address climate change. Even a climate progressive nation such as the UK is currently failing to meet CO2 emission targets set by the Paris Agreement,1 hence there is significant pressure for the development of innovative technologies to overcome this global challenge. The UK government's target to reach net-zero emissions by 2050 is to be partly facilitated by carbon sequestration. The UK's largest carbon capture plant, due to be operational by 2021, hopes to capture 40,000 tonnes of CO2 per annum - equivalent to the emissions of 22,000 cars.Both commercial and industrial applications of carbon dioxide are relatively limited, therefore these soon to be vast stores of captured CO2 present an exciting opportunity for an alternative fuel source. This project aims to develop metal nanoparticle catalysts that will facilitate both the thermal and photocatalytic reduction of CO2 to more valuable products such as formic acid which can serve as a hydrogen storage material, methanol which can act as a combustion fuel or as a C1-feedstock for the production of various fine chemicals, methane or even higher alkanes.The principal focus of this work will be to employ functionalized polymer immobilized ionic liquids (PIIL) as supports to stabilize gold nanoparticles, control their growth (size distribution and shape), modify surface electronic properties and explore whether catalyst-support interactions can be used to control efficacy. PIIL supports are advantageous over bespoke ligands as they are more affordable, robust, and are not prone to leaching enabling the catalyst to be recovered and recycled. The Doherty group has previously found that PIIL supports are highly beneficial in promoting the activity, stability, and selectivity of gold nanoparticle catalysts towards the reduction of small molecules.2 Reports have shown that polymeric ionic liquids also have a high CO2 absorption capacity in addition to fast rates of CO2 adsorption/desorption,3 therefore we intend to extend this technology towards the thermal and light driven reduction of CO2. Advanced analytical techniques such as TEM, XPS, EDX, powder-XRD, TGA and solid-state NMR spectroscopy will be utilized to determine the catalyst composition while DRIFT, XPS and in situ FTIR will be used to probe the catalyst surface and to study CO2 adsorption. A detailed understanding of surface-support interactions will provide insight on the factors that influence catalyst activity and product distribution, facilitating the development of an optimum catalyst with a stable activity profile suitable for scale-up.Relevant EPSRC research areas: Catalysis, Materials for Energy Applications, Carbon Capture and Storage, Renewable Energy1. Anderson, K.; Broderick, J. F.; Stoddard, I., A Factor of Two: How the Mitigation Plans of 'Climate Progressive' Nations Fall Far Short of Paris-Compliant Pathways. Clim. Policy 2020, 1-15.2. Doherty, S.; Knight, J. G.; et al., Highly Selective and Solvent-Dependent Reduction of Nitrobenzene to N-Phenylhydroxylamine, Azoxybenzene, and Aniline Catalyzed by Phosphino-Modified Polymer Immobilized Ionic Liquid-Stabilized AuNPs. ACS Catal. 2019, 9 (6), 4777-4791.3. Zulfiqar, S.; Sarwar, M. I.; Mecerreyes, D. Polymeric Ionic Liquids for CO2 Capture and Separation: Potential, Progress and Challenges. Polym. Chem. 2015, 6 (36), 6435-6451.