Dr. Weiqiao Deng of Dalian Institute of Chemical Physics of the Chinese Academy of Sciences and his colleagues recently reported a class of cobalt/aluminium-coordinated conjugated microporous polymers (Co-CMP/Al-CMP) that exhibit outstanding CO2 capture and conversion performance at atmospheric pressure and room temperature. These polymers can store CO2 with adsorption capacities comparable to metal-organic frameworks. These findings have been published on Nature Communications.
CO2 emissions are a serious problem in the establishment of a sustainable society and are driving the implementation of green chemistry concepts. These emissions are widely considered to be a primary factor in global climate change. The development of efficient and cost-effective methods for CO2 capture and sequestration is an important goal for human society over the course of this century. To replace the currently employed industrial method of chemical sorption of CO2, which has high energy demands, researchers have developed processes by which CO2 is adsorbed over zeolite, carbon, alumina and metal-organic frameworks (MOFs). It has also been proposed that captured CO2 be deposited in underground reservoirs. Although the formation of cyclic carbonate via homogeneous catalysts has been industrialized, the process requires high temperatures and pressures, and product separation is difficult. The development of a heterogeneous catalyst for synthesizing cyclic carbonate at mild conditions remains a challenge. The combination of CO2 capture and conversion is an attractive strategy for efficiently reducing CO2 emissions. It is essential that the materials used in this strategy be able to capture and convert CO2 at atmospheric pressure and room temperature with only heat from the surrounding environment to avoid the generation of new CO2.
The polymers Co-CMP and Al-CMP, both of which have high BET surface areas, displayed excellent CO2 adsorption capacities. Furthermore, when co-catalysed with a quaternary ammonium salt TBAB, Co-CMP and Al-CMP displayed exceptionally high catalytic activities in the conversion of PO and CO2 to PC at atmospheric pressure and room temperature. A single catalyst (Co-CMP) could be reused up to 22 times without a significant decrease in catalytic activity. These findings provide a new direction for the simultaneous capture and conversion of CO2.
CMPs, found in 2007, are a new class of porous materials with an extended p-conjugation in an amorphous organic framework. Owing to the wide-ranging flexibility in the choice and design of components and the available control of pore parameters, these polymers can be tailored for use in various applications, such as gas storage, electronics and catalysis. Dr. Deng’s research group has been devoted themselves into development and application of CMPs. For example, they demonstrated a strategy to enhance the hydrogen storage capacity of CMP by doping with Li+ ions in 2009 (Angew. Chem. Int. Ed., 2010, 49, 3330-3333). They also reported for the first time the surface superhydrophobicity of the CMP as well as their excellent adsorption performance for oils and organic solvents in 2011(Energy & Environmental Science 2011, 4, 2062–2065).
Source: Nature Communications, 2013, doi:10.1038
