Entry Date:
August 17, 2010

Thin Films of MOFs for Gas Separation Membranes and CO2 Reduction Electrocatalysis

Principal Investigator Mircea Dinca


Deposition of MOFs as thin films and membranes -- Current synthetic methods are not useful for the deposition of MOFs directly and selectively on conductive surfaces, as needed for instance for the use of MOFs as electrocatalysts. More generally, the lack of good methods for making thin films and membranes prevents the use of these promising materials in practical settings and is a key requirement for future developments. We are devising new methods that afford the synthesis and deposition of MOF thin films, membranes, and nanoparticles directly on conductive surfaces, through electrochemistry. We have shown recently that tens of microns-thick films of MOF-5 can be deposited selectively (from among a host of other possible products) from a solution containing Zn2+ and terephthalic acid in only minutes at room temperature. This contrasts with typical solvothermal techniques, which require high temperature and extended time. The method also allows phase-selection via potential control. We are currently exploring the scope of our electrodeposition approach, and the effect of variables such as deposition potential, electrode surface, concentration, and electrolyte. Developing conformal film growth methods, as allowed by electrochemistry, will lead us to MOF-based membranes for gas separations, which are currently some of the most energy-intensive processes in the world.

CO2 reduction using MOF thin films - Owing to the generally insulating nature of MOFs, these have not been used almost at all for electrocatalysis applications. As such, thin films are needed to explore their potential to function as electrocatalysts. Enabled in part by our MOF thin-film deposition method described above, we are studying CO2 electroreduction uisng MOFs. The use of CO2 as a feedstock for value-added chemicals is an important target for sustainability. Students involved in these projects will become experts in electrochemical and solvothermal techniques and will be involved in organic synthesis, as necessary for designing and synthesizing new ligands. We also aim to develop soft, solution methods that would enable facile patterning of various solid-state materials on the underlying surface, which is very challenging using current strategies.