Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO₂ Fixation Reactions

Abstract

CO is a major greenhouse gas responsible for global warming and can act as an abundant and inexpensive C1 source for enhancing the chain length/functionalization of a wide range of reactive organic molecules. It is moderately reactive, nontoxic and renewable. Thus, CO fixation reactions are important to meet the global challenges, that is, to mitigate the concentration of CO in the atmosphere through its fruitful utilization, which is of great interest from economic and environmental perspectives. Various metallic nanoparticles as well as metal oxides can be supported over high surface area porous materials and the resulting nanomaterial can act as heterogeneous and reusable solid catalyst for CO fixation reactions for the synthesis of a large number of fuels, natural products agrochemicals, and pharmaceutical compounds. Here we present an overview of the recent progress as well as promising future of metal/metal oxide nanoparticles supported over porous nanomaterials as heterogeneous catalysts for a wide spectrum of these CO fixation reactions.

A Highly Stable Triazole‐Functionalized Metal–Organic Framework Integrated with Exposed Metal Sites for Selective CO2 Capture and Conversion

“…In addition to selective CO 2 capture, another attractive means of effective CO 2 elimination is the direct chemical conversion of CO 2 into value‐added chemicals (e.g., dimethyl carbonates, cyclic carbonates, N,N′‐disubstituted ureas, or formic acid) . Therefore, after the establishment of permanent porosity, excellent stability, and highly selective CO 2 capture, the existence of a high density of Lewis acidic metal sites was further examined for the catalytic activity of 1 towards the chemical conversion of CO 2 to cyclic carbonates.…”

“…In addition to selective CO 2 capture, another attractive means of effective CO 2 elimination is the direct chemicalc onversion of CO 2 into value-added chemicals (e.g.,d imethyl carbonates, cyclic carbonates,N ,N'-disubstituted ureas, or formic acid). [23] Therefore, after the establishment of permanent porosity,e xcellent stability,a nd highly selectiveC O 2 capture, the existence of ah igh density of Lewis acidic metal sites was further examined for the catalytic activity of 1 towards the chemi-cal conversion of CO 2 to cyclic carbonates.A lthough several MOFs as heterogeneous catalysts have been demonstrated for the chemical conversion of CO 2 into cyclic carbonates, mostly under the conditions of high temperature and high CO 2 pressure. [24] To gether with significant uptake and limited reports for chemicalc onversion of CO 2 into cyclic carbonates at ambient conditions, [25] the catalytic activity of 1 was explored under milder conditions (30- 40 8Ca nd 1atm).…”

Catalytic Non-redox Carbon Dioxide Fixation in Cyclic Carbonates

“…[13][14][15] Because of their importance, many catalysts have been developed for cyclic carbonate formation, including ionic liquids, [16][17][18] metal complexes, 15,19 functional polymers, [20][21][22] ammonium and phosphonium salts, 23,24 metal-organic frameworks (MOFs), 8,25,26 hydrogen-bonding catalysts, 7,27,28 and supported catalysts. 29,30 Homogeneous, organometallic catalysts have often proved effective with well-defined mechanisms and notable catalytic activity, 10,11 but the added cost of separations and purification of metallic species…”

Porous Organic Polymers for CO2 Storage and Conversion Reactions

“…It is noteworthy to mention that CO 2 is moderately reactive, abundant and renewable source of carbon to be employed as C1 building block for the synthesis of a wide range of fuels and value added fine chemicals or intermediates . These CO 2 utilization or fixation reactions can be broadly classified into three categories, i) CO 2 reduction to CO, CH 3 OH, CH 4 , HCHO, HCO 2 H or higher hydrocarbons, ii) reactions involving new C−C, C−O, C−N bond formations and iii) synthesis of organic and inorganic carbamates, cyclic carbonates or polycarbonates .…”