Professor Fei Honghan's research group of Tongji University designed N-heterocyclic carbene functional MOF material to realize efficient and high selective catalytic reduction of CO2

Although CO2 is the main greenhouse gas, it is a cheap and nontoxic C1 raw material in the field of green organic chemistry At present, there are still great challenges in improving the activity and selectivity of CO 2 catalytic conversion system The crystal porous structure represented by metal organic framework (MOF) provides a new idea for catalytic conversion of CO 2, which is expected to achieve high activity and selectivity through the precise control of lattice matrix Professor Fei Honghan, School of chemical science and engineering, Tongji University, has been committed to the research of functional MOF materials for a long time The research results on catalytic reduction of CO2 by functional MOF materials are as follows: "in situ generation of an N-heterocyclic carbene functional metal – organizational framework by postsynthetic life exchange: efficient and selective hydration of CO2 ”It was published in the international top Chemical Journal angel Chem Int ed (DOI: 10.1002 / anie 201813064) N-heterocyclic carbene (NHC) shows excellent catalytic performance in many CO 2 curing reactions The research team in MOF field has long tried to immobilize the activated and non coordination metal NHC into MOF framework, but the development is slow The main reason is that the functional MOF precursor of imidazolium salt is prone to MOF structure collapse in the process of activation to carbene Recently, Professor Fei Honghan's research group used ligand exchange method to generate carbene in situ and modify it into highly stable zirconium based MOF, constructed a NHC functional MOF without transition metal coordination, and applied the MOF to the catalytic reduction of CO2 under mild conditions In this method, the in-situ activated carbene ligands are modified to MOF framework by the dynamic equilibrium of solid-liquid two phases in the process of dissolving carboxylic acid ligands in inorganic base during ligand exchange, so as to avoid the collapse of crystal structure caused by the traditional carbene formation requiring strong alkali (such as Nah, Kot BU) treatment Compared with the homogeneous carbene catalyst, the MOF material showed higher catalytic activity in the hydrosilylation of CO 2, and its pore size effect made carbene site easier to activate the silane substrate and achieve quantitative transformation (> 99%) More importantly, among many products, only the methoxy substituted reduction product (CH3O [Si]) with the highest chemical added value can diffuse freely in the MOF channel, with excellent catalytic selectivity (> 99%), and can be hydrolyzed to methanol (CH3OH) quantitatively Finally, an efficient catalytic cycle from CO2 to CH3OH can be realized at room temperature and atmospheric pressure All of them are much higher than the reported homogeneous carbene catalyst The first author of the paper is Zhang Xu, a master of the research group, and Wei Guangfeng, a teacher, provides theoretical calculation support for this paper Wei Guangfeng and Fei Honghan are co authors of communication, and Tongji University School of chemical science and engineering is the only communication unit.