Our answer is simple and straightforward, no different.   Electrocatalysis, you can understand it as one of the branches of the electrochemical discipline, or you can understand it as an electrical application of catalysis. Whether it is the extension of electrochemistry in catalysis or the application of catalysis in the field of electrochemistry, the essence of catalysis remains the same, and the mechanisms in electrocatalysis and catalysis are the same.   What is the essence of catalysis? It is to change the kinetic rate of a chemical reaction, either speeding it up or slowing it down. Note that it is also important to keep in mind that it does not change the thermodynamic equilibrium of the chemical reaction, and that whether or not a chemical can occur is mainly limited by the thermodynamic equilibrium, i.e., the Gibbs function changes. This is something so many people forget over time. Many chemical reactions, although thermodynamically feasible, cannot proceed at significant reaction rates, and must be catalyzed to lower their own reaction activation energy to increase the reaction rate.   Catalyzed reactions simply change the reaction path of the system, as described by the transition state theory in the figure below: without a catalyst, the activation energy of a chemical reaction is much higher than it would be with a catalyst, but the addition of a catalyst changes the course of the reaction. For example, what might be a 4-step reaction without a catalyst might become a 7-step reaction with the addition of a catalyst. Although the activation energy is so much lower, the rate of the chemical reaction may increase by up to a factor of ten. The most typical example is ammonia synthesis, which may not react for tens of thousands of years without the addition of an iron catalyst, but with the addition of a small amount of catalyst, the ammonia industry was created.   This is somewhat similar to our work, the goal is constant and does not change. But some may be easy to accomplish, others may be really hard. The catalyst is communication, tools, consultation, literature, experience and other measures in the work.   Above is the meaning of catalyzing and back to electrochemistry.   The same is true in electrochemistry. Electrocatalysis is mainly used to increase the rate of chemical reaction by making catalysts as electrodes or modifying catalyst materials on the surface of electrodes.   The reaction rate in electrochemistry is related to the activity of the catalyst in addition to the electric field distribution electrolyte at the solid/liquid interface. Therefore, the catalyst is only one of the factors to improve the electrochemical reaction rate, remember to focus on the catalyst when studying the electrocatalytic system. And what can affect the electric field distribution includes the electrode potential.   Since it is a catalytic reaction, the chemical reaction history is usually at least two, including the adsorption of molecules or ions.   Here are some examples of common electrocatalytic systems in industry:   1, chlor-alkali industry, through the saturated brine, the anode generates chlorine gas, the cathode generates hydrogen, the tank voltage is generally 3-4.5V, the anode catalyst is generally Ti-based loaded with Co, Sn, Pt, Pd, and other transition metal composite catalysts, the cathode catalyst with the transition metal composite catalyst.   2、Fuel cell, the best catalyst for fuel cell is Pt, Pd, Pt-Co alloy and so on, in the electrocatalytic system the geometry of the catalyst has a significant effect on the performance of the catalyst.   3、Organic small molecule oxidation, CO molecule oxidation, methanol and formic acid oxidation, organic fluoride oxidation. The better catalysts are Pt, nano type Pt catalyst, Pt-Ru alloy and so on.   4、Photocatalysis, the more popular direction is photocatalytic hydrogen production, the more popular catalysts are TiO2, CdS, ZnO and so on.