We are starting a new and exciting Master of Science Programme with entry from the academic year 2022/23.
This programme is aimed to develop the specialist chemistry skills that industry, academia and society need for a sustainable world.
Find out more and join us at: https://www.sheffield.ac.uk/postgraduate/taught/courses/2022/chemistry-and-sustainability-msc
Zeolite Y was used as a support for the synthesis of Sn and Ga doped zeolites aimed at the isomerization of glucose to fructose. Though these materials are inactive in water, they are active in methanol and we could ascertain a reaction pathway involving a hydride shift for the interconversion of glucose to fructose and mannose, and a Brønsted acid pathway with the formation of a methyl fructoside intermediate and its hydrolysis to fructose if water was added afterwards. By using characterizations comprising: chemisorption, XPS, XRD, HAADF-STEM and EXAFS; it was possible to demonstrate that a straightforward impregnation protocol for the preparation of our catalysts, led to Sn/Y mainly consisting of small SnO2 clusters on the external surface of the zeolite, whereas Ga/Y consisting of highly dispersed Ga species mostly inside the zeolite pores; and a catalytic activity that appears to be dominated by Brønsted acid sites.
Read more at: https://www.sciencedirect.com/science/article/pii/S0926860X22002125
Our group member Baozhai Han has successfully defended his PhD dissertation entitled: “Silver based catalysts for the selective oxidation of cyclic hydrocarbons under mild conditions”. Well done Dr. Han!
The direct selective oxidation of hydrocarbons is an important process both in industry and academia to produce oxygen containing compounds by the transformation of petrochemical feedstock, like methane, cyclohexane, ethylbenzene, cyclooctane. In the oxidation process, molecular oxygen is employed for the partial oxidation of hydrocarbons to desired corresponding alcohols or ketones. Nowadays, more than 90% of organic compounds are derived from petrochemicals that are saturated hydrocarbons.
Silver supported metal nanoparticles were developed to carry out these transformations at a low energetic cost.
Our group member Changyan Zhou successuflly defended her PhD dissertation entitled: “Zeolite Catalysts for Water Treatment: Catalytic Wet Peroxide
Oxidation of Phenol”. Well done Dr. Zhou!
The discharge of wastewater into the environment without adequate treatment aggravates
water shortage worldwide, which prompts the development of efficient wastewater treatment technology as an active area of research in recent years. The catalytic wet peroxide oxidation based on Fenton and Fenton-like reactions, as one of the most promising techniques, was applied in the decomposition of the aromatic pollutants in water by using phenol as representative compound in this research.
Microporous metal oxides with an additional metal within the framework were developed for their potential to create confined metal active sites for large scale water purification processes.
Merging hydrogen (H2) evolution with oxidative organic synthesis in a semiconductor-mediated photoredox reaction is extremely attractive because the clean H2 fuel and high-value chemicals can be coproduced under mild conditions using light as the sole energy input. Following this dual-functional photocatalytic strategy, a dreamlike reaction pathway for constructing C-C/C-X (X = C, N, O, S) bonds from abundant and readily available X-H bond-containing compounds with concomitant release of H2 can be readily fulfilled without the need of external chemical reagents, thus offering a green and fascinating organic synthetic strategy. In this review, we begin by presenting a concise overview on the general background of traditional photocatalytic H2 production and then focus on the fundamental principles of cooperative photoredox coupling of selective organic synthesis and H2 production by simultaneous utilization of photoexcited electrons and holes over semiconductor-based catalysts to meet the economic and sustainability goal.
Read more about this exciting area of research in our Review at https://pubs.acs.org/doi/abs/10.1021/acs.chemrev.1c00197
Granulated aerogels can be of interest in terms of their sound absorption performance in the audio frequency range. However, there is still no thorough understanding of the complex physical phenomena which are responsible for their observed acoustical properties. This work is an attempt to address this gap through advanced material characterization methods and mathematical modelling. Aerogel samples are produced through a two-step, acid-base sol-gel process, with sol silica concentration and density being the main variables. Their pore structure is carefully characterized by nitrogen sorption analysis and scanning electron microscopy. The acoustical properties of hard-backed granular silica aerogels are measured in an impedance tube and the results predicted accurately with the adopted theoretical model.
Find out more about our paper at: https://asa.scitation.org/doi/full/10.1121/10.0005200
Read about a recent publication in Nature Communications on the synthesis of novel materials capable to capture CO2 and transform it into useful chemicals:
The performance of transition metal hydroxides, as cocatalysts for CO2 photoreduction, is significantly limited by their inherent weaknesses of poor conductivity and stacked structure. Herein, we report the rational assembly of a series of transition metal hydroxides on graphene to act as a cocatalyst ensemble for efficient CO2 photoreduction. In particular, with the Ru-dye as visible light photosensitizer, hierarchical Ni(OH)2 nanosheet arrays-graphene (Ni(OH)2-GR) composites exhibit superior photoactivity and selectivity, which remarkably surpass other counterparts and most of analogous hybrid photocatalyst system. The origin of such superior performance of Ni(OH)2-GR is attributed to its appropriate synergy on the enhanced adsorption of CO2, increased active sites for CO2 reduction and improved charge carriers separation/transfer. This work is anticipated to spur rationally designing efficient earth-abundant transition metal hydroxides-based cocatalysts on graphene and other two-dimension platforms for artificial reduction of CO2 to solar chemicals and fuels.
Read more at: https://www.nature.com/articles/s41467-020-18944-1
Our group member James Railson successuflly defended his PhD dissertation entitled: “Developing the synthesis of novel TiO2 and Nb2O5 supports and their applications to the selective oxidation of alkanes”. Well done Dr. Railton!
The theme of this project was based on selective alkane oxidation with oxygen as the sole oxidant in a solvent-free system by means of shape selective catalysis. This was to provide a competitor for the application of ‘green’ synthesis of linear primary alcohols, which are exceptionally relevant compounds for the fine chemicals industry from surfactants and coatings to cosmetics.
Microporous metal oxides with an additional metal within the framework were developed for their potential to create confined metal active sites.
One of our group members, Changyan Zhou, recently published a paper in Chemical Papers (in press).
Some materials that are active heterogeneous catalysts for the breakdown of non-ionic aromatic solutes in water are found to act as potentiometric sensitizers for same solutes. The present work establishes an application for catalysts beyond catalysis itself. The use of catalysts as sensitizers is recommended for wider uptake and in reverse, to screen candidate catalysts.
Read more at: https://link.springer.com/article/10.1007/s11696-020-01212-3
Dr. Marco Conte 01/07/2020
Conte Catalysis Group - University of Sheffield, UK