Dr Alberto Roldan Martinez
Alberto Roldan

I finished a four years degree (BSc) in Chemistry with a physical-chemistry speciality at the University of Barcelona in 2006. There, I also carried out an Experimental Masters (MSc) where I sought to explore the effect of synthesized magnetite nano-particles deposited together with electrochemical copper films. During my PhD at University Rovira i Virgili, I used computational methods including Density Functional Theory (DFT) with several functionals to explore surfaces, wires, nano-particles, and supported nano-clusters. Besides structure modelling, I studied reaction mechanisms for the synthesis of epoxides and the activation of molecular oxygen by metal nanoparticles. There was a long-standing controversy about the nano-particle size responsible for the high activity of gold to catalyse the activation and dissociation of molecular oxygen, which we were able to resolve through DFT simulations. I found that the local electronic structure of the gold nanoparticles determines the reactivity and stability of activated oxygen. I verified it with a micro-kinetic model on nano-particles of different sizes with good agreement with experiment.

In 2010 the physical-chemistry department at the University Rovira i Virgili awarded me with a PhD which received the recognition of the Best Thesis in Computational Chemistry in 2011. By the time I finished the PhD, I had twelve peer-reviewed publications; two of them were from a visiting fellowship to Milano-Bicocca University, in collaboration with Prof. Pacchioni for a project modelling the reactivity of metallic clusters supported on oxide’s step surfaces, funded by COST-D41 European collaborative grant. I also had presented my research in seven national and international conferences and events.

I joined Prof. de Leeuw’s group in October 2010 at University College London as the computational lead in EPSRC funded programmes investigating carbon dioxide reduction catalysed by iron sulfides and oxide surfaces in direct collaboration with experimental groups. The materials investigated included ferromagnetic spinels and thio-spinel systems with detailed electronic and structural characterisation, which resulted in a perfect match with experimental determination of synchrotron radiation techniques. We obtained computational-experiment proof-of-concept on the reactivity of these sulfides towards CO2 conversion under mild conditions with a detailed mechanistic reaction profile of relevance to the Origin of Life hypothesis based on sulfide containing ocean floor vents. In addition, I was part of other projects including reactivity on two-dimensional materials, oxides and metallic surfaces.

This successful research activity was recognised in 2012 when I was awarded the Ramsay Memorial Fellowship Trust allowing me to develop further in the field of materials and catalytic chemistry. I expanded my research scope studying the early stages of crystal formation and the photo-activity of quantum dots in collaboration with experimentalist besides developing models of the study of dopant segregation. I have also developed and tested a methodology to incorporate Density Functional Theory results in a more realistic model using micro-kinetic analysis. In these models, the characteristic times for mass transfer and surface processes are derived from the reaction time reciprocal to the rate constant considering multiple experimental conditions. I have implemented the results on the carbon dioxide conversion on greigite surfaces resulting in the optimisation of the experimental conditions. This and my previous positions enabled me to become part of several research teams and networks, including CO2Chem, 4CU and Energy Materials expanding my range of collaborations. I became part of the Thomas Young Centre, which has strong links to the London Centre for Nanotechnology providing opportunities for collaboration and knowledge sharing. Over the last years, I have disseminated my research in presentations at several internationally recognized conferences.

I was appointed a University Research Fellow (URF) in 2015 by Cardiff University, an independent five-year fellowship to investigate the formation mechanism of supported nanostructures as well as surface dynamic processes such as sintering.This position offers me the opportunity to collaborate directly with the Cardiff Catalyst Institute ‒ a leading centre in Europe in the field of supported metal nanoparticle catalysts.