oxide-zeotype bifunctional catalysts efficient for the conversion of CO and CO2 to light olefins – OXZEO

Light olefins (C2-C4) are key intermediates of the chemical industry. They are produced by steam cracking or catalytic cracking, two very energy-intensive processes currently using fossil resources. A more eco-efficient and dedicated production is a major challenge. In the future, it could be based on syngas obtained from different resources (fossil, biomass, waste). Contrary to the Fischer-Tropsch process, the Ox-Zeo process, which combines a hydrogenating oxide and an acid zeotype, allows to obtain high selectivity to light olefins with a high stability. However, the CO2 selectivity must be decreased and the catalytic activity be improved. Recent works showed that mixtures of ZnZrCeOx and SAPO-34 or RUB-13 can achieve very high selectivity to light olefins (>80%) and low CO2 selectivity (5%) at 300 °C and Patm. These new bifunctional catalysts are also efficient for the conversion of CO2 to light olefins and therefore deserve further investigations.
However, the previous works were focused on catalytic performance and it appears necessary to overcome the scientific challenges by determining the role of oxygen vacancies, OH species (and associated frustrated pairs) as well as the mobility of O species, by clarifying the role of each element (coordination, electronic state) and their interactions in mixed oxides such as ZnCeZrOx and by determining the role of acidity (nature, strength, density) on the reaction mechanism within the SAPO-34 and RUB-13 zeotype and on the olefin/paraffin ratio.
The OXZEO project, which aims to answer these questions, should shed new light on the knowledge of ZnCeZrOx oxides combined with either SAPO-34 or RUB-13 zeotypes to selectively and stably convert CO and CO2 into light olefins and finally propose new formulations based on structure-properties relationships.
For that purpose, a fundamental and interdisciplinary work composed of 4 packages is proposed. It includes the coordination of the project, the synthesis and characterization of ZnCeZrOx oxides and zeotypes SAPO-34, RUB-13 with well-defined and modulated properties, the measurement of the catalytic properties of oxide-zeotype mixtures for the conversion of CO and CO2 to light olefins, for the conversion of methanol to light olefins in the presence of CO, CO2, H2 and advanced characterization based on in situ/operando techniques, some of which have never been deployed.
The work will be carried out by a consortium of researchers and engineers from IRCELYON and IC2MP whose expertise is complementary. The tasks, which are equally distributed between the two laboratories, will be carried out in synergy. To succeed this project, a funding of 475 keuros is requested to the ANR. It includes the recruitment of 3 M2 students, a PhD student and 2 post-doctoral fellows.
The project may have important economic and societal benefits as it aims to develop a process dedicated to the sustainable production of light olefins from syngas or captured CO2. It will generate new fundamental knowledge about the latest generation of Ox-Zeo catalysts which will be valorized through publications in high impact journals and high-level international congresses. This knowledge can be transposed to other oxides and other zeotypes working in synergy by tandem catalysis for different reactions. Patenting is not excluded if very efficient catalysts are discovered. Dissemination to industry will also be carried out. The project can have an important echo in the scientific community of heterogeneous catalysis and can make France emerge in the international competition in particular with China.