New progress has been made in the study of carbon dioxide hydrogenated aromatics

Li Can, Ph.D., Dr. Li Zelong, Ph.D. student Qu Yuan straight and others of the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences have made new progress in the research of CO2 catalytic hydrogenation and preparation of aromatics: CO2 is directly selectively converted into aromatics through a series catalyst system. The study was published recently in Joule.
Li Can team has long been committed to solar photo catalysis, photo-catalysis, electro-catalytic decomposition of water hydrogen and CO2 conversion work
China
. The conversion of CO2 into fuels and chemicals using clean energy hydrogen is an important strategy for achieving CO2 reduction and sustainable use of carbon resources. Aromatics are one of the most important basic chemical raw materials in the synthesis of organic materials, using aromatics to synthesize a large number of polymer materials, such as polystyrene, phenol resin, nylon, and polybiodiaphenyl glycol resin. Traditional aromatic hydrocarbon synthesis methods are mainly the lysing of pyroacetic oil and the path of methanol aromatic hydrocarbons (MTA) based on coal methanol developed in recent years, both of which rely on fossil resources (oil and coal). Therefore, the use of hydrogen from renewable energy to convert CO2 into high value-added aromatics, so that CO2 in the form of polymer material storage, not only to achieve CO2 carbon resource utilization, but also to reduce CO2, has important strategic significance. However, CO2 is an inert molecule in thermodynamics, and there are great difficulties and challenges in realizing the active and highly selective transformation of CO2.
in this work, Li Can's team further constructed the ZnZrO/ZSM-5 series catalyst system based on the study of CO2 hydrogenated methanol on ZnZrO solid solutions (Science Advances 2017) and CO2's study of hydrogenated preparation of low-carbon olefins (ACS Catal. 2017) on ZnZrO series systems. The catalyst converts CO2 hydrogenation to aromatics with high selectivity, and when the one-way conversion rate of CO2 is 14%, the selectivity of aromatics in hydrocarbons is 73% to 78%, while the selectivity of CO can be lowered to 44%. It is found that the key to CO2 hydrogenation to aromatics is the effective synergy of series catalysts. Infrared spectroscopy, chemical capture, and experiments show that CO2 and H2 are actively produced on ZnZrO solid solution oxides to produce CHxO intermediate species, which migrate from the ZnZrO surface to molecular sieve pathways to complete aromatic hydrocarbon generation. Synergy mechanisms between series catalysts, as well as surface migration of the key intermediate species CHxO, enable co2 hydrogenation directly to aromatics reactions in thermodynamic and dynamic coupling. The moderate amount of H2O generated in the CO2 hydrogenation reaction has a significant effect on the aromatic composition of olefins by inhibiting the adsorption of weak acid levels of low-carbon olefins in molecular sieves. Due to the presence of H2O and CO2 in the reaction system, it provides a weak oxidizing atmosphere, inhibits the generation of polycyclic aromatic hydrocarbons on the catalyst, and prolongs the life of the catalyst, which does not show significant infestion during the 100-hour reaction process. This technology has opened up new ideas for the transformation of CCO2.