Bio-inspired (Fe,Ni)S nano-catalysts for CO2 conversion

Despite the high thermodynamic stability of CO2, biological systems are capable of both activating the molecule and converting it into a range of organic molecules, all of which under moderate conditions. It is clear that, if we were able to emulate Nature and successfully convert CO2 into useful chemical intermediates without the need for extreme reaction conditions, the benefits would be enormous: One of the major gases responsible for climate change would become an important feedstock for the chemical and pharmaceutical industries! Iron-nickel sulfide membranes formed in the warm, alkaline springs on the Archaean ocean floor are increasingly considered to be the early catalysts for a series of chemical reactions leading to the emergence of life. The anaerobic production of acetate, formaldehyde, amino acids and the nucleic acid bases - the organic precursor molecules of life - are thought to have been catalyzed by small cubane (Fe,Ni)S clusters (for example Fe5NiS8), which are structurally similar to the surfaces of present day sulfide minerals such as greigite (Fe3S4) and mackinawite (FeS).Contemporary confirmation of the importance of sulfide clusters as catalysts is provided by a number of proteins essential to modern anaerobic life forms, such as ferredoxins, hydrogenases, carbon monoxide dehydrogenase (CODH) or acetyl-coenzyme A synthetase (ACS), all of which retain cubane (Fe,Ni)S clusters with a greigite-like local structure, either as electron transfer sites or as active sites to metabolise volatiles such as H2, CO and CO2. In view of the importance of (Fe,Ni)S minerals as catalysts for pre-biotic CO2 conversion, we propose employing a robust combination of state-of-the-art computation and experiment in a grand challenge to design, synthesise, test, characterise, evaluate and produce for scale-up novel iron-nickel sulfide nano-catalysts for the activation and chemical modification of CO2. The design of the (Ni,Fe)S nano-particles is inspired by the active sites in modern biological systems, which are tailored to the complex redox processes in the conversion of CO2 to biomass.The scientific outcome of the Project will be the design and development of a new class of sulphide catalysts, tailored specifically to the reduction and conversion of CO2 into chemical feedstock molecules, followed by the fabrication of an automated pilot device. Specific deliverables include:i. Atomic-level understanding of the effect of size, surface structure and composition on stabilities, the redox properties and catalytic activities of (Fe,Ni)S nano-catalysts;ii. Development of novel synthesis methods of Fe-M-S nano-clusters and -particles with tailored catalytic properties (M = Ni and other promising transition metal dopants);iii. Rapid production and electro-catalytic screening of lead nano-catalysts for the activation/conversion of CO2;iv. Development and application of a new integrated design-synthesis-screening approach to produce effective nano-catalysts for desired reactions;v. Construction of a prototype device capable of catalysing low-temperature reactions of CO2 into products at typical low-voltages, that can be obtained from solar energy; vi. Identification of optimum process for scale-up in Stage 2, from the Economic, Environmental and Societal Impact evaluationThe target at the end-point of Stage 1 is the fabrication of a photo-electrochemical reactor capable of harvesting solar energy to (i) recover CO2 from carbon capture process streams, (ii) combine it with hydrogen, and (iii) catalyse the reaction into product. In Stage 2 of the project, the prototype will be developed into a scaled-up commercially viable device, using optimum catalyst(s) in terms of (i) reactivity/selectivity towards the desired reaction; (ii) economic impact; and (iii) environmental, ethical and societal considerations.

The beneficiaries range from (i) the general public, (ii) the Government and public sector, to (iii) a variety of industries and even (iv) charities and voluntary organisations. (i) General Public We are all under threat from the potentially disastrous effects of climate change, such as rising sea levels and extreme weather conditions, a robust method for the reduction of CO2 levels will benefit all humans as well as the Earth's flora and fauna. (ii) Commercial Sector Not only our project partners Johnson Matthey, but catalyst industries in general will benefit from the development of the novel sulfide catalysts for the conversion of CO2, especially as they will be designed for use under ambient conditions and at low voltages. As catalysts generally catalyse a number of reactions, these nano-materials are potentially very widely applicable. Producers of formic acid also benefit from this new, clean and moderate synthesis route to formic acid, which is an important chemical feedstock molecule, potentially applicable as an alternative, direct fuel for fuel cells in portable electronics applications, e.g. laptops and mobile phones. Finally, this catalytic system for the conversion of CO2 would benefit the oil and gas industry, the car and aviation industry and any other industries where CO2 is a by-product, which needs to be removed. (iii) Government/Public Sector With ever more stringent legislation put in place to guarantee a cascade of international agreements to reduce CO2 and other greenhouse gases to acceptable levels, viable routes to a proven reduction of CO2 are clearly of prime importance to policy makers and legislators. (iv) Third Sector More speculative beneficiaries of this research are charities and voluntary organisations. With climate change leading to more frequent weather-induced disasters, such as hurricanes, floods and droughts, the call on voluntary aid organisations is increasing rapidly and climate stabilisation would alleviate this burden to sustainable levels. Measures to ensure that the beneficiaries will become aware of the research outputs include * Close collaboration with industrial project partners Johnson Matthey, who will lead on the patenting of the new catalysts, will increase the UK's competitiveness on the global market. Once a patent has been filed for the sulfide catalysts, the route will be open to other industries to develop their own modifications and/or build the JM catalyst into their own catalytic process devices * IP arising from the research will be dealt with according to UCL's standard procedures (in agreement with contractual arrangements with JM). Exploitation of IP is facilitated by UCL Business and UCL Advances, which are independent specialist units dedicated to knowledge transfer and the advancement of innovation in research * Two workshops during Stage 1 of the project will have technical sessions to inform scientists/engineers in academia and industry on the scientific/technological developments of the project, and more general sessions for relevant public and commercial sector workers on the advances of the project, also including debate of ethical and societal concerns * Engagement with policy makers and legislators to raise awareness of the benefits and potentials of the new CO2 conversion system and the economic, environmental and societal implications, as determined by the Life Cycle Analysis * Engagement with the wider general public through a series of outreach events, in cooperation with the UCL Public Engagement Unit, opened as a result of UCL and its partners becoming one of six national Beacons of Public Engagement * Training for the researchers in societal and ethical impacts of the research through the European Science Communication Teachers network - ESConet (www.esconet.org) * Media training, advice and promotion through dedicated UCL Media Relation Team