As a form of energy, electricity is not the most practical for many applications because it is difficult to store and transport efficiently. The storage, transport and extraction technologies of electric energy in cheap and efficient ways becomes necessary for its widespread use. One plausible approach is to collect and store it in chemical bonds as chemical fuel, and then to be extracted on demand via the oxidation of chemical fuels in fuel cell device, which could buffer and smooth the power supply and offset the intermittent nature of renewable energy sources.
The oxidation of water or small hydrocarbon molecules are extremely important anodic half-cell reaction in the development of chemical fuel synthesis or direct fuel cell technology. In order for the wide industrial implementation, the robust, efficient and cost-effective electrocatalysts are highly desirable. In this Doctoral Thesis, different approaches to develop various Prussian blue analogues thin film on the conductive substrate for the electrocatalytic water oxidation reaction in different media are presented. Electrochemical, spectroscopic and structural studies were employed to assess the genuine catalytic activity, long-term stability and corrosion resistance under harsh oxidizing condition. Furthermore, cobalt hexacyanoferrate (CoFePB) has demonstrated to be able to selectively promote the electrochemical oxidation of formic acid/formate to CO2 with full faradaic efficiency in aqueous solution over a large pH range from 1 to 13, albeit at high overpotentials. We have made extensive use of electrochemical impedance to examine the dynamic kinetics and thereby to get more mechanistic understanding on electrocatalysis. Finally, a definitive proof of concept of liquid formate fuel cell device was built with CoFePB as anode and Ce4+ as oxidant on carbon felt. This simple and noble-metal-free fuel cell would exhibit the promising application in the research fields for energy capture and generation.