Regulating adsorption performance of zeolites by pre-activation in electric fields
Kaifei Chen, Zhi Gen Yu, Seyed Hesam Mousavi, Ranjeet Singh, Qinfen Gu, Randall Q. Snurr, Paul A. Webley, Gang Kevin Li
Abstract
Abstract While multiple external stimuli (e.g., temperature, light, pressure) have been reported to regulate gas adsorption, limited studies have been conducted on controlling molecular admission in nanopores through the application of electric fields (E-field). Here we show gas adsorption capacity and selectivity in zeolite molecular sieves can be regulated by an external E-field. Through E-field pre-activation during degassing, several zeolites exhibited enhanced CO 2 adsorption and decreased CH 4 and N 2 adsorptions, improving the CO 2 /CH 4 and CO 2 /N 2 separation selectivity by at least 25%. The enhanced separation performance of the zeolites pre-activated by E-field was maintained in multiple adsorption/desorption cycles. Powder X-ray diffraction analysis and ab initio computational studies revealed that the cation relocation and framework expansion induced by the E-field accounted for the changes in gas adsorption capacities. These findings demonstrate a regulation approach to sharpen the molecular sieving capability by E-fields and open new avenues for carbon capture and molecular separations.