Invited
Electrochemical conversion of Metal-Organic Frameworks into porous electrocatalysts with tailored composition and catalytic activity for solar fuel reactions

Metal Organic Frameworks (MOFs) are a subclass of coordination polymers consisting of metal clusters and multi-topic organic linkers. Due to their high surface area, porosity and tuneable chemical and photo-physical properties, MOFs are arousing widespread attention to be used in applications such as gas storage and separation, chemical catalysis, sensing, and photocatalysis. Yet, slow charge-transport kinetics often limit the performance of MOF-based electrochemical devices. Thus, great efforts have been made to convert MOFs into high-surface-area inorganic or organic–inorganic–hybrid nanomaterials (e.g., metal sulfides, metal oxides, and their corresponding carbon composites) with improved conductivity and electrocatalytic activity, and their subsequent utilization in practical electrochemical energy conversion devices.

Currently, high temperature conversion of Metal-Organic Frameworks (MOFs) is considered an attractive means to produce high surface area, efficient inorganic electrocatalysts. Yet, the harsh synthesis conditions often make it challenging to control the chemical structure (especially the density and distribution of electrocatalytically-active sites) of the derived material. Thus, up until now only a few studies focused on disclosing the relation between active site properties and electrocatalytic activity for these types of MOF-derived materials. Hence, there is a clear need to develop new strategies for converting MOFs into catalytically active inorganic nanomaterials in a milder, sustainable and controllable fashion, while having the ability to fine-tune the chemical composition of the final products.

In this talk, we will present our general, simple, room-temperature method for the electrochemical conversion of MOF (EC-MOF) films into porous, amorphous electrocatalysts. Control over EC-MOF parameters such as scan-rate and potential window enables us to manipulate the rate and degree of MOF conversion. Consequently, as opposed to conventional high-temperature MOF conversion, we could fine-tune the porosity and chemical composition of the obtained electrocatalyst. Demonstrations for the utilization of EC-MOF in solar fuel related reactions (HER, OER and CO₂ reduction) will be given.