Understanding Bio-induced Selectivity in Nanoparticle Catalyst Manufacture

This project proposes to make highly selective nano-particulate catalysts using a novel method ('biocasting') for a set of defined catalytic reactions and to develop understanding of how to control the catalyst manufacturing process to achieve the desired selectivity which is not readily achieved using chemical manufacturing alone.. Controlled growth of metal nanoparticles in various naturally occurring and modified bacteria will be used to produce the required catalysts supported on cell surfaces.Previous work, has demonstrated that bacteria can be used as a catalyst support for nanoparticulate metals, including platinum and palladium. The process involves reducing the metal enzymatically from a salt solution over a bacterial culture, with templating and stabilisation achieved using biochemical components at the living/nonliving interface, followed by post-processing, which kills the bacterial cells but retains the special catalytic properties of nanoparticles. Such materials have been shown to provide selectivity towards desirable products in catalytic reactions including double bond isomerisation and selective hydrogenation, but at present there is a lack of understanding of why this superior selectivity occurs. One factor may be the crystal structure, including the ratios of edge to terrace and corner atoms which influence the adsorption of reactants upon the catalyst surface. Another effect is the rate of diffusion of reactants to the metal surface. This proposal will develop understanding of why the nanoparticles give rise to superior catalytic selectivity, and thus will enable the rational design and production of nanoparticles for given applications. The present proposal will seek to clean the biotemplated metal particles using chemical and electrochemical methods in order to control the metal cluster morphology, and to block selectively certain active sites on the catalyst using Bi, Pb, sulphur or bacterially derived agents incorporated at the synthesis stage. By switching on or off active sites in this way and associated characterization and testing of the catalysts, it will be possible to identify which types of sites are associated with favourable selectivity in chemical transformations.The produced catalysts will be characterized using a range of techniques which will elucidate information about the nanoparticle size, shape, cluster structure, redox behaviour, electrochemical and spectroscopic behaviour (SERS, XPS, XRD, TPD, DRIFTS and CV). Catalytic selectivity will be studied in a range of selective hydrogenation and double bond isomerisation reactions. The ultimate goal is to replace Lindlar catalysts based on lead modified palladium and other transition metals with more environmentally benign alternatives; previous studies in ours and collaborators' laboratories have shown that the precious metal can be supplemented with cheap metals such as Fe and can even be sourced as such mixtures from waste and scrap for economic manufacture.Current methods for nanoparticle manufacture are not 'clean' and/or not scalable. The major advantage of biomanufacturing is its scalability; we have routinely grown several kilos of the bacteria at the 600 litre scale in our pilot plant. As part of this project we will make Bio-Pd preparations at the 30-100 litre scale (batch cultures), checking the small-scale and large-scale NP products for conserved properties, and also stock aliquots for shelf-life evaluation.

The research will deliver a highly selective catalyst, and demonstrate potential scale-up, which will be desirable to industrial companies for technology transfer and further development. Major industrial catalyst manufacturers such as Johnson Matthey and SMEs, for example Catalytic Technology Management Limited (CTML), are interested in alternative catalyst production routes leading to catalysts which display higher selectivity in industrial syntheses than their conventional counterparts. A first stage market research survey (CTML, University of Birmingham) indicated market niches and opportunities for commercialisation. The techniques developed under this project could potentially lead to manufacture of industrial catalysts from waste materials, including catalysts for energy production. This will lead to reduction in the waste of raw materials by using un-selective catalysts, recovery of precious metals (e.g. from jewellery or electronic goods) for recycling, and improved manufacturing of chemicals without undesirable side reactions. The project team have considerable expertise in technology transfer activities, particularly Prof Macaskie, who was awarded a London Technology Network Business Fellowship, which targets various networking and outreaching events to access potential collaboration and exploitation events. Kevin Deplanche (named RA), currently holds a Medici Fellowship (University of Birmingham) concurrently with an EPSRC Follow on Fund Fellowship, in which he develops a new class of Pd/Au catalyst and seeks market opportunities for the biomanufactured precious metal. Angela Murray is a BBSRC Enterprise Fellow, working within Macaskie's group, who will advise on technology transfer and media opportunities. J. Wood was invited to give a keynote lecture in Cairo, Egypt, by Sabrycorp, a Nano-technology consultancy company which specialises in introducing nano-tech in the Middle East. It is expected that he will make return visits, and that this could lead to dissemination and tech-transfer in Middle Eastern Countries. Wood is also working on other energy related research, such as upgrading of heavy oils (EP/E057977/1), and intends to seek opportunities for the use of nano-particulate catalysts in heavy oil upgrading, through future grant applications, and possible industrial collaboration. Letters of support have been obtained from several companies, who are aware of the project and its aims, such that commercialisation of the proposed nanoparticulate catalysts could be expected to take place 3-5 years after the end of the proposed project. The work will be widely disseminated through a range of events, which will include academic publications and conferences, technical presentations at subject group meetings (e.g. IChemE), media dissemination (radio and TV), and school visits. We will also bid for a Royal Society Summer Exhibition on 'Clean Chemistry' in 2013. A website, incorporating video on demand reports about the project, presentations and selected information will be set up. The technology transfer and intellectual property rights concerning the project will be managed by the Technology Transfer companies of the Universities of Birmingham and Cardiff. Alta Innovations is the Tech Transfer Company at the University of Birmingham, who will work closely with Cardiff, including applying for patents to protect the intellectual property rights generated under this project. The project will deliver three research fellows, who will be highly trained in bio-catalytic manufacture as well as skilled in surface analytical techniques, chemical synthesis and business development. It is expected that Joint Venture Licensing or spin out will occur around 2012, and product manufacture and first income streams would follow towards 2014. Further information about the impact of this project can be found in the Impact Statement, including a road map diagram of plan for delivery impact.