ABSTRACT
Increasing demand for sustainable and clean energy is calling for the next-generation energy conversion and storage technologies such as fuel cells, water electrolyzers, CO2 /N2 reduction electrolyzers, metal-air batteries, etc. All these electrochemical processes involve oxygen electrocatalysis. Boosting the intrinsic activity and the active-site density through rational design of metal-organic frameworks (MOFs) and metal-organic gels (MOGs) as precursors represents a new approach toward improving oxygen electrocatalysis efficiency. MOFs/MOGs afford a broad selection of combinations between metal nodes and organic linkers and are known to produce electrocatalysts with high surface areas, variable porosity, and excellent activity after pyrolysis. Some recent studies on MOFs/MOGs for oxygen electrocatalysis and their new perspectives in synthesis, characterization, and performance are discussed. New insights on the structural and compositional design in MOF/MOG-derived oxygen electrocatalysts are summarized. Critical challenges and future research directions are also outlined.
ABSTRACT
The reaction pathway of n-butane selective oxidation to maleic anhydride (MA) over vanadium phosphorous oxide (VO)2P2O7 catalysts was systematically probed using in situ transient Diffuse Reflectance Infrared Fourier-Transform Spectroscopy (DRIFTS) in high temperature/high pressure chamber. The unsaturated and saturated noncyclic carbonyl species were determined to be intermediates in n-butane selective oxidation to MA. Furan was detected on the surface of the (VO)2P2O7 catalysts in 1-butene, 1,3-butadiene selective oxidation. It was deduced that furan ring was cleaved to form unsaturated noncyclic carbonyl species before its conversion to MA. Based on these results and in comparison with the literature, a simplified scheme of the reaction network structure can be proposed for n-butane selective oxidation to maleic anhydride.
