Green chemistry is the design of new environmentally friendly chemical processes. It is a high stakes area of which catalysis, which makes chemical transformations more efficient and less energy-consuming, is one of the pillars. Thanks to the franco-singaporean scientific cooperation programme MERLION, Dr Ning Yan, heads the Lab for Green Catalysis in the Department of Chemical and Biomolecular Engineering (ChBE) of the National University of Singapore (NUS) and Dr Karine Philippot who manages the Metal Nanoparticle Engineering team at the CNRS’ Coordination Chemistry Laboratory (LCC) at the University of Toulouse in France – had the opportunity to collaborate on a research project on the enhancement of lignin by hydrogenolysis on nanoparticle catalysts. Back on this experience with the Principal Investigators of the two laboratories.
The application of sustainable development to chemistry
Green chemistry is the application of sustainable development principles to chemistry, spread over 12 principles, in order to eliminate the use or the generation of substances harmful to the environment. Catalysis, which makes chemical transformations more efficient and less energy-consuming, is a pillar of green chemistry. However, to render new chemical reactions environmentally friendly and economically viable for future industrial applications, major scientific breakthroughs are needed, notably in the development of catalysts based on metal nanoparticles, considered the future of green catalysis.
In France, the activities of the team of Dr Philippot focus on the controlled synthesis of complex nanoparticles and nanomaterials based on metals or metallic oxides, their applications and properties. The end result of these work is to be used in applications in various fields such as catalysis, energy, health (medical imaging), or microelectronics. In the area of catalysis, the laboratory develops new precision catalysis based on metallic nanoparticles or oxides (whether in solution or on a support). In Singapore, Dr Yan’s laboratory works on modern nano-catalysts and the development of new and extremely stable nano-catalysts, which are efficient (they are active and selective) and recyclable so as to improve industrial chemical transformations or to attain new chemical reactions not achievable using conventional catalysts.
How was the collaboration formed between your two laboratories?
Dr. Ning Yan – we met at a congress on Catalysis and Metallic Nanoparticles in 2009 in Wroclaw, in Poland. We thus found out that our research activities and scientific approaches were very complementary. Our laboratories share common interests, we have since remained in contact. In 2012, when I was guest editor for a special issue of the scientific review “Catalysis Today”, I invited Karine to participate in this special issue by submitting a joint article. In 2013, when I heard about the MERLION call for projects, I immediately contacted Karine to think about a common project and submit an application. Among the diverse subjects that interested us to develop together, we chose the study of the conversion of lignin, and our project was accepted.
Do you have the feeling that this collaboration would not have been possible without the MERLION programme ?
NY – Yes, it is sure. MERLION was a great opportunity, a real trigger. Going beyond the funding, the programme provided a framework within which the collaboration became possible. The financing of the researchers’ mobility as given by the MERLION project was not our primary motivation, but it proved to be perfectly suited to the putting in place of a collaboration where numerous travels were in fact necessary.
KP – The MERLION Project allowed us to maintain exchanges in the form of visits of researchers and students, and beyond, to firm up our collaboration through joint works. It made this cooperation possible by offering a framework and a dedicated financing.
IN BRIEF: CATALYSTS AND NANOPARTICLES
– discovered in the 18th century, catalysis is the acceleration of a chemical reaction with the help of a substance present in a small quantity : the catalyst. It is widely used in chemical industries and in drugs, where 80% of the processes are due to a catalytic reaction.
A catalyst is a compound capable of accelerating, of facilitating the process and of directing a chemical reaction, typically under milder conditions of temperature and pressure, towards the formation of wished-for products without undergoing changes during the process. It remains in its form at the end of the reaction.
Nanoparticles are very small particles. The prefix “nano” comes from the Greek and means “very small”. These particles are of the size of the order of 10-9m, which corresponds to a diameter of 30,000 times smaller than that of a strand of hair.
A nanoparticle metal does not have the same properties (optical, magnetic, catalytic etc.) as the solid metal. These properties vary a lot depending on the size of the nanoparticles.
Why are very small powders and compounds used in catalysis
Powders are used in catalysis due to the small diameter of the particles that make up the powders. This small size also increases the active surface of the catalyst considerably. Indeed, the (chemical) reactions are possible only with the catalyst surface.
The nanoparticles used in catalysis offer an optimal interaction surface because of their spherical shape and their size.
What are the major achievements and the main results of this collaboration?
NY – To study a catalytic process is to go beyond a chemical reaction; it is to understand and describe all the steps in the process starting from the reactants and going all the way to the products. We had previously analysed many common catalysts, but for a more accurate evaluation, to better understand the phenomenon at play, we needed catalysts with very specific characteristics in terms of surface states, composition and particle size.
Dr Philippot’s team synthesizes very good nanoparticle catalysts, with very clean surfaces, and very fine and calibrated particles. That is why this collaboration was extremely interesting. We were able to evaluate the different combination of bimetallic nano-catalysts and to establish what worked best and why.
KP – I confirm entirely the complementarity of the skills and research work of our two teams. It is certainly what permitted us to work together, and what motivates us to want to continue. This collaboration gave us the chance to test our nanomaterials in catalysis reactions that we could not have achieved in the laboratory. Conversely, this has enabled Dr Ning Yan’s laboratory to access different and very accurate nanomaterials.
This joint MERLION project is now ended ; what did you gain from it ?
NY – First of all, from a scientific point of view, the project achieved its objectives and this has proven very satisfying. We have, moreover, published two joint articles for scientific journals, which is also very important.
Going beyond these results, we have demonstrated our aptitude to work together and we have established mutual trust, which is very valuable to me.
With this experience, and the complementarity of our expertise, we have gained the will and the capacity to continue the collaboration beyond the scope of the PHC Merlion programme.
KP – I completely agree with what has just been said. I would add that this project has given (us) a better understanding of our two teams’ skills and savoir-faire, shown through research objectives other than those initially identified, and the submission of a project funding request in France to the ANR (National Research Agency) which was unfortunately denied.
A point to improve is perhaps the possibility of a longer funding period (over 5 years for example), to allow for more time to obtain other funding to go beyond the PHC MERLION.
Do you have other collaborative projects within the PHC MERLION?
NY – I do not at present have any intention of collaborating with other laboratories, but I would like to pursue the collaboration with Dr Philippot’s team, as part of a bigger project, with joint funding and that which, therefore, is beyond the scope of the PHC MERLION. We would also be interested in a MERLION Ph.D or financing a thesis under joint supervision, but it is unfortunately very difficult today in Singapore to get Ph.D students because of sharply declining government quotas.
KP – To date, I do not have other joint PHC (MERLION) projects with another team in Singapore, but I wish to keenly pursue the collaboration with Dr Yan, especially for a MERLION Ph.D, with a joint funding from our two teams. An ANR-NRF project would also provide an interesting framework within which to continue our common activities and to explore new research objectives. The cooperation tool, PHC MERLION that allows collaborations to happen by supplying the means to realize meetings and exchanges between laboratories, would appear to be a springboard for future joint actions between France and Singapore.
Original article written and released in French by Cécile BROSOLO (www.lepetitjournal.com/singapour), June 1, 2016, translated by Audrey TAY, Institut Français Singapore.