A.O.Ibhadon PhD CChem FRSC MIM SFHEA MSPE
Reader Catalysis & Reactor Engineering; Visiting Professor, Panjab University, Chandigarh, India
Graduated with a doctorate under ‘General Regulations’ in Physical Polymer Chemistry from the University of Birmingham in 1989 thanks to a Commonwealth Scholarship. PhD work (distinction in first year assessment, thus enabling transfer to general regulations), involved the mechanical properties (Fracture Mechanics) and crystallization behaviour of semi-crystalline polymers (the kinetics and thermodynamics of crystallization in semi-crystalline isotactic polypropylene). Work on crystallization after ‘partial melting’ was put into commercial exploitation in the ‘Thermoforming’ operations of Metal Box (Oxon), enabling the production of plastic products (for example plates) with enhanced fracture toughness, impact resistance as well as environmental stress cracking. This also formed the basis of about eight articles published in the Journal of Applied Polymer Science, including articles such as ‘Crystallization Regimes in Semicrystalline Polymers’, ‘Physical Ageing in Isotactic Polypropylene’ and ‘Strain hardening behaviour in semicrystalline Polymers’
A postdoctoral Fellowship at the School of Chemical Engineering and Advanced Materials at the University of Newcastle then followed my PhD study and a lectureship appointment at the University of Hull in 1995.
At the University of Hull, I have been director of teaching and learning (2000-2004), Director of Studies (2011-2015), Head of the Centre for Environmental and Marine Sciences (2015-2016) and have served in the University Quality assurance committee, Faculty Teaching and Learning Committee, Academic Standards Committee. I am currently the Programme Director, Department of Chemical Engineering (2017-present) working with the Director of Studies and the Head of Department to deliver a great student experience in teaching and learning.
Background in Physical Chemistry (PhD) and lectureship in the same area have shaped research direction as demonstrated by the themes listed below. Work in these areas have received substantial and significant research funding from the EU, Royal Society, Engineering and Physical Sciences Research Council, EU Proof of Concept(PoC) grant, EU leadership grant, the Newton Bhaba Fund as well as the Commonwealth with total research income about £6.7M as Principal and Co-investigator as below
Competitively Won Research Income since 2016
2021 LC-SC3-RES-26-20 EU H2020 Renewable Energy
The EU €3,990,731.00 P-1
2021 Newton Bhaba RLWK Newton Fund £27,615. 55 Co-I
2020 PhD Immunomodulating Nanoparticles Commonwealth
2019 New Coating Technology for chemical synthesis EU Leadership €1,177,925 (UoH 40%) Spin Out Co-I
2019 Synthesis of Inorganic Sensors Commonwealth £39,820.38 ( to UoH) P-I
2018 Microfluidic Sensors Global Challenge £26,536 (to UoH) P-1
2018 Advanced Materials for Water Treatment Newton Fund £37,100 (to UoH) P-1
2018 Photocatalytic Quantum Dots Newton Fund £15,400 (to UoH) P-I
2017 Micro-Reactors Active Pharm. Ingredients(APIs) EU Funding £42,000 (to UoH) P-I
2016 Advanced Nanoporous Materials Newton Fund £70,000 (to UoH) P-I
2016 Catalyst Coated Tubular Reactors Innovate UK £550,000,(Spin-Out),UoH 40% Co-I
2016 Catalyst Coated Tubular Reactors EU PoC Grant €150,000 (Spin-out) UoH 40% Co-I
2016 Catalyst Coated Tubular Reactors and Distributor EPSRC £35,000; Spin-out UoH 40% Co-I
-2016 Microwave, Acoustic and Plasma Synthesis EU FP7 £3.6M, £425k to UoH P-I
Income since 2016(PI = £644,321.83; IP funding £1,719,755; total funding since 2016 is £2,575,342.47).
Research Theme One
Catalysis for the Synthesis of Fine Chemicals and Active Pharmaceutical Ingredients
The increasing use of catalysts places a demand on the need for new synthetic methods and better ways of characterizing catalyst systems especially in terms of their surface properties on which many applications depend. Catalysts are indispensable in fine chemical synthesis, selective hydrogenations, automotive exhaust treatment, industrial effluent and municipal waste treatment, technological developments in fuel cells, photovoltaic cells and pollution abatement technologies and these range from hierarchical porous composites, hybrids, nanoparticles and crystalline composites, to host – guest composites. In all catalyst systems, the requirement is high activity, remarkable selectivity and resistance to deactivation. Composite catalysts have attracted continuous attention because they are being used to meet practical performance requirements of high activity, high selectivity and stability in the chemical industry. This review covers recent developments in supported nanoparticles for Carbon-Carbon cross coupling reactions and other chemical transformations and will be of interest to both scientists and engineers from aca¬demia and industry working in the fields of pharmaceuticals and the fine chemicals industry that need insight into recent patent literature and applications.
Catalytic hydrogenations in Continuous Flow Reactors
It is recognised that novel and robust catalysts, capable of combining high activity with excellent selectivity and substrate compatibility as well as novel reactor concepts are required to ensure atom economy, process efficiency and environmental sustainability in chemical processing. For example, the manufacture of chemicals, the main business of the chemical industry, requires developments and innovation at the catalyst, microreactor and flow technology frontiers so that processes can be executed with higher energy efficiency, higher input of inexpensive and readily available raw materials, and increased facility of separation and recovery of products. Catalysts with high selectivity and activity control the overall efficiency of a process by avoid¬ing unwanted side-reactions and increasing the conversion per unit time.
It is also now recognized that continuous synthesis in flow is one of the major technologies that can enable process intensification and the development of substantially cleaner, safer and more energy efficient chemical processes. Consequently, in this work, we report a novel method for the synthesis of think homogeneous coatings of intermetallic catalyst materials by solution combustion and microfluidics which were then used to coat the walls of a 0.50m id, 1 m, tubular reactor fabricated from disposable silica capillaries. The reactor was then used to execute selected end-user nitro reduction reactions of pharmaceutical importance. Gas –liquid profiles along reactor path was measured using a novel technique based on Endoscopic Presence Raman Spectroscopy, enabling us to obtain ‘active kinetic data’ over novel catalysts.
Research Theme Two
Solar Refinery and Artificial Photosynthesis
The photo catalytic and photo electrochemical Conversion of CO2 and H2O using sunlight to renewable fuels for transportation and energy storage is important for global energy security and also mitigating the effect of climate change. We carry out research on key disruptive photo electrochemical (PEC) and biosynthetic light harvesting technologies in a global research and innovation effort, to address key research, innovation and industrial adoption bottlenecks in the conversion of CO2 into renewable fuels from direct sunlight. These bottlenecks include: low solar-to-fuel efficiency (STH) and stability of materials under realistic reaction conditions, high production cost and poor scalability of lab-based systems in development for the conversion of solar energy to stable storable chemicals and fuels.
To achieve energy security while mitigating the effect of climate change, future energy systems will need to rely, either wholly or predominantly, on renewable energy sources and pathways. The expected reduced dependence on fossil resources will require renewable sources to produce high energy density storage compounds and fuels as strategic reserves and for seasonal storage. This is necessary because fossil fuels or compounds derived from them, including crude oil fractions, are currently the main forms of energy storage. Consequently, new energy storage compounds, possessing unlimited storage capabilities will need to be found and developed for continuous operation to meet future energy needs. Viable candidates for energy storage (hydrogen, methanol, methane, and ethanol) have been the subject of many reviews for large-scale implementation and storage (Schüth, F. Chemical Compounds for Energy Storage, Chemie Ingenieur Technik 2011, 83, No. 11, 1984–1993). For the formation of renewable chemicals, wind, or solar thermal energy is harvested primarily as electric energy, the direct storage of which is difficult on a large scale. This is because the needed energy is most effectively stored in the form of chemical compounds and chemical bonds allow, by a wide margin, the storage of energy with the highest density (Figure 1.3a). These requirements effectively rule out solids (Ferdi Schüth, Chemie Ingenieur Technik 2011, 83, No. 11, 1984–1993).
Our extensive literature review, analysis of global market trends, cost analysis, assessment of global warming potential (GWP) and acidification potential (AP), energy security assessment and patent review of next generation renewable energy, sources, storage compounds, engine ignition systems and fuels and based on this and the analysis by (Dominik Bongartz & Schutt et al. Applied Energy, 2018, 231, 757–767; Chemie Ingenieur Technik 2011, 83, 11, 1984–1993) enables us to research and develop two production pathways for dimethyl ether from sunlight, as a next generation renewable fuel, namely (a) a photoelectrochemical CO2 and H2O conversion system and (b) a biosynthetic OMCP-CEIP light harvesting CO2 and H2O conversion system.
Our aim is to deliver a unique technological solution (illustrated in Figure 1.3b), that combines a breakthrough photobiological technology (OMCP-CEIP-MS), with novel photo-electro catalysis (PEC) for the sustainable conversion of direct sunlight and CO2 into biofuel/renewable intermediates (e.g. H2/CO) that are in turn converted to dimethyl ether – DME (an alternative renewable fuel for transport and energy).
Dimethyl ether production System
CO2 utilisation via conversion into fuels such as dimethyl ether (DME) or raw materials such as methanol using physical or chemical methods offers an approach to sustainably and economically abate and recycle CO2 and eliminate the economic liability and health & safety concerns associated with geological CO2 storage in carbon capture and storage (CCS) technology. Various technologies, including thermocatalysis, electrocatalysis, photocatalysis, and biochemical technology, can be used for this purpose. Of these, the solar-driven photo-catalytic process has proved to be a promising technology (Roy et al, ASC Nano, 2010, 4, 1259-1278). However, photo-catalytic technology has low conversion efficiency and low utilization of solar energy, which vary significantly from one technology to another. To tackle this challenge, a photo-catalytic system that can make efficient use of solar energy is the most desired development. Solar light absorption and electron transportation in conventional photocatalytic materials are difficult especially in single photocatalyst systems because: (a) semiconductor has a lower light absorption capability than phytochroms, although ionic doping and semiconductor coupling have been used to broaden the spectrum responsive range.
Recent research indicates that introducing disordering and defected surfaces can significantly increase light absorption (Chen et al, Science, 2011, 331. 746-750); (b) photo-catalytic systems are, unlike phytochroms, found in nature, in which the photo-generated electrons can be exploited by 100%. Compared to phytochroms, the electron transportation velocity of semiconductors is significantly lower, resulting in reduced separation efficiency of the photo-generating carriers. Although P/N hetero-junctions have been reported, the separation effect is not significant; (c) nanofabrication of photo-catalysts is an effective way to improve the photo-catalyst activity. Recent studies indicate that the photo-generating carriers can be effectively separated by the space confinement of nano-domains (Liu et al, J. Am. Chem. Soc., 2010, 132 14385-14387).
Owing to high photo-chemical and chemical stability required, transitional metal oxides and their composites have been investigated. Among these, titania is one of the most active candidates. The major drawback for the use of oxides is that their ionic character imposes band gaps too large (> 3 eV) to utilise a significant portion of sunlight (~4 % of the solar spectrum) for photocatalytic splitting of water (Chen et al, Nat. Rev. Mater. 2017, 2, 1–17). Band-gap tuning via hetero-structure formation, is a promising strategy to reach a compromise between solar light absorption and reduction potential (Ghafoor et al, N. Sci. Rep. 2017, 7 (1), 255).
Furthermore, inspired by natural photosynthesis, attention has been devoted recently to the development of Z-scheme photocatalyst system, consisting of two narrow band gap semiconductors (PCI and PCII) respectively, (Figure 1.4a). The band positions of PCI and PCII should be aligned such that it results in the utilization of electrons and holes with stronger reducing and oxidizing abilities, but on separate active sites that also inhibits electron-hole recombination. This unique charge transfer pathway, using a redox or solid-state mediator, or in a mediator free system, has attracted recent attention (Chen et al, Nat. Rev. Mater. 2017, 2, 1–17). Moreover, recent studies (Yan et al, Chem. Commun., 2011, 47, 5632-5634) demonstrated that the exposed active facets of photo-catalysts play a crucial role in activation and photoreaction.
In summary, the major challenges with photo-catalytic CO2 conversion systems lie in (i) material instability and low performance in practical applications; (ii) difficulty in making use of the full range of the solar spectrum; (iii) low product selectivity. The use of organic metal complexes-based homogeneous photo-catalysis, having a fast photo-induced electron transfer velocity, is closer to plant photosynthesis in Nature and presents a strategy to address these limitations as demonstrated by recent research (Sato et al, Angew. Chem. Int. Ed., 2010, 49, 5101–5105) that show that organic metal complexes show high activity in the photo-catalytic conversion of carbon dioxide under visible light irradiation. The study stated that by selecting suitable metals ions and designing organic ligands, both the HOMO and LUMO energy levels of organic metal complexes can be flexibly modulated to match the reduction potential of CO2 (Takeda et al, J. Am. Chem. Soc., 2008, 130, 2023–2031) and the poly-electron transfer process can be realized through the design of thermally stable ligands.
Photoelectrochemical CO2 reduction and H2O splitting
The photoelectrochemical reduction of CO2 competes with water reduction in aqueous media, i.e. H2 generation and the direct photo reduction is a challenge because CO2 is thermodynamically stable, showing a high energy barrier (Chang et al, Energy Environ. Sci., 2016, 9, 2177-2196) that impedes its activation and conversion in a multistep and complicated reaction pathway. For this reason, the conversion efficiency and reaction selectivity are largely compromised. The main CO2 reduction products are C1 (CO, CH4, CH3OH, CH2O, and HCOOH) and C2 (C2H4, C2H5OH, and CH3COOH), which are more desirable for applications in energy storage and transportation and as fuels because of their higher energy density and value. Electrochemical reduction allows the production of C1 with > 95 Faradaic efficiency (FE) (Liu et al, Nature 2016, 537, 382-386), C2 with 60 % FE (Braun et al, J. Power Sources 301 (2016) 219) and C3 products with 8 %. The main advantage of a PEC reactor compared to a photocatalytic device is that its compartmentalised design allows for the separation of reduction and oxidation products. (Martens et al, Chem. Soc. Rev. 2014, 23, 7957-8194). PEC reactor design for CO2 reduction is limited, however, the designs proposed for electrochemical CO2 reduction can be adopted and these are based on a cathode electrocatalyst immobilized in a gas diffusion layer, which overcomes the limitations of low CO2 concentration at the cathode interface. We will use selective ion-exchange membrane to separate the anolyte and catholyte and surface modification to improve photoelectrode efficiency and stability