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Lecture

Electrocatalysis Fundamentals

In course

CH-421: Catalysis for energy storage

This course covers the fundamental and applied aspects of electrocatalysis related to renewable energy conversion and storage. The focus is on catalysis for hydrogen evolution, oxygen evolution, and CO2 reduction reactions. Both homogeneous and heterogeneo ...

Description

This lecture covers the fundamentals of electrocatalysis, including topics such as exchange current density, Tafel slope, and parameters for judging catalyst performance. It also discusses the practicality of catalysts based on exchange current density and Tafel slope.

Instructor

Xile Hu

Xile Hu was born in 1978 in Putian, southeastern China. He entered the Peking University in Beijing in 1996. Besides learning too little chemistry, his biggest regret in the college was not able to correct his southern accent in Mandarin. After graduated from PKU, he went to the United States and began his doctoral studies at the University of California, San Diego. In December 2004, he finished with a Ph.D. in chemistry and some fond memories of the beautiful city of San Diego. He then moved to the Los Angeles area and become a postdoctoral scholar at the California Institute of Technology. There he enjoyed numerous stimulating scientific (and other) discussions with friends and colleagues. He also made plenty of friends outside the campus and was a frequent in many local Chinese restaurants. In 2007, after two pleasant visits to Switzerland, he decided to move across the continent one more time and join the faculty of the École Polytechnique Fédérale de Lausanne (EPFL). He now directs the Laboratory of Inorganic Synthesis and Catalysis and is interested in developing chemistry for synthesis, energy and sustainability.

Official source

Related concepts (32)

Reaction rate

The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time. Reaction rates can vary dramatically. For example, the oxidative rusting of iron under Earth's atmosphere is a slow reaction that can take many years, but the combustion of cellulose in a fire is a reaction that takes place in fractions of a second.

Tafel equation

The Tafel equation is an equation in electrochemical kinetics relating the rate of an electrochemical reaction to the overpotential. The Tafel equation was first deduced experimentally and was later shown to have a theoretical justification. The equation is named after Swiss chemist Julius Tafel." It describes how the electrical current through an electrode depends on the voltage difference between the electrode and the bulk electrolyte for a simple, unimolecular redox reaction ".

Reaction mechanism

In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction.

Chemical reaction

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.

Overpotential

In electrochemistry, overpotential is the potential difference (voltage) between a half-reaction's thermodynamically-determined reduction potential and the potential at which the redox event is experimentally observed. The term is directly related to a cell's voltage efficiency. In an electrolytic cell the existence of overpotential implies that the cell requires more energy than thermodynamically expected to drive a reaction. In a galvanic cell the existence of overpotential means less energy is recovered than thermodynamics predicts.

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