Solar photothermo-catalytic conversion of CO2 on phyllosilicates modified with Ni and CeO2

One of the strategies to mitigate the greenhouse effect is converting the CO 2 into high-added value products. In this work, a photothermo-catalytic approach, using peculiar Ni-phyllosilicates samples, was applied for the CO 2 conversion into solar fuels. In particular, the Ni-phyllosilicates were modified with the introduction of the Ce ions in their structure and successively they were covered with the CeO 2 semiconductor. The structural, morphological, textural, optical and reducibility properties as well as the interaction with CO 2 were investigated. The Ni/ Ce-phyllosilicate covered with CeO 2 achieved a CO 2 conversion of 87% after 5 hours of photothermo-catalytic test using simulated solar irradiation at 120 degrees C, producing 15.8 mu mol/g cat center dot h of CO and 5.6 mu mol/g cat center dot h of CH 4 . The same sample was tested in an integrated approach where the CO 2 was evolved by the catalytic oxidation of toluene and then was converted into CO and CH 4 , obtaining a CO 2 conversion of 50% and 8.8 mu mol CO /g cat center dot h and 3.3 mu mol CH4 /g cat center dot h. The presence of Ni in the phyllosilicates structure guaranteed a good catalytic stability whereas the deposition of CeO 2 allowed to exploit the improved thermal (redox) properties of cerium oxide and favoured the CO 2 adsorption on its basic sites and oxygen vacancies. Furthermore, the high surface area of the assynthetized Ni-phyllosilicates permitted to efficiently expose the CeO 2 surface-active sites to the solar radiation. The here investigated catalysts showed versatile properties ideal for hybrid catalytic approaches as the photothermo-catalysis, allowing to propose new solutions for the CO 2 valorization.