Development of carbon-based heterogeneous (photo)catalysts

In many cases, chemical industry uses precious metals or metal oxides based catalysts. These catalysts are expensive and often are not highly selective increasing waste and producing greenhouse gases. In contrast, carbon based materials are environmentally acceptable and cheap combining an efficient use of energy and resources. In heterogeneous materials, electrical, thermal and photophysical properties can be precisely controlled and modulated providing a broad range of applications. We have demonstrated that organic dyes can be successfully used to construct a surface supported nanomaterials.(1) Covalently modified surfaces with (photo)active units, become increasingly important as they offer stability and show more superior properties in contrast to supramolecular interactions or individual components. We are interested in (photo)catalytic processes whereby highly reactive intermediates(2) can be generated and used under mild conditions to construct novel metal-free hybrid catalysts for a given application. Different projects are available in this area, for example in: (a) Oxidation of alkanes as a feedstock of high-value-added chemicals. Oxidation of cheap alkanes to high-value-added chemicals is an important industrial challenge. Selectivity of oxidation using various industrially relevant catalytic systems, is poor due to inertness of the C-H bonds. Thus, the chemical process is problematic to control, leading to over-oxidation.

So far, the production of terephthalic acid and cyclohexanone from alkanes is achieved. However, it uses metal catalysts and a large quantity of acid to yield only moderate selectivity. The project focuses on design and testing of recyclable graphene based catalysts to decrease the negative economic and environmental impact of these processes. (b) Oxygen reduction metal-free electrocatalysts. Oxygen reduction is central to many industrially relevant applications such as energy storage and conversion devices. However, slow kinetics of the electrochemical oxygen reduction is a limitation, and requires a catalyst such as Pt. Current developments focus on a replacement of platinum with a cheaper and more efficient metals. The project will focus on the development of metal free carbon-based alternatives. (c) Development of photocatalysts for metal-free type of C-C bond formation.

The project aims at the development of: 1) the metal free hybrid photocatalysts and 2) the analytical platform to assess their oxidation and reduction abilities. Our choice of photocatalysts’s design will be directed by two objectives: (i) modification of the graphene surface by planar, electron-rich molecules sensitive to photochemical ET with high extinction coefficient in visible region; (ii) methodology allowing quick, efficient and solution-processable functionalisation. (d) Metal-free catalysis for the degradation of organic pollutants. The project aims to develop an analytical platform for degradation of pollutants e.g. organic dyes in waste water using metal-free carbon based (photo)catalysts. Techniques: interdisciplinary projects, wet chemistry, organic synthesis, materials synthesis, Raman, FTIR, XRD, SEM, TGA, spectrophotometric methods, synchrotron, kinetics.