What Is Catalytic Activity?

Catalytic activity, which refers to the ability of a substance to catalyze, is one of the important properties of a catalyst. The catalytic activity of a substance is for a given chemical reaction. In industrial production, it is often expressed in terms of the amount of raw material reactants converted per unit volume (or mass) of the catalyst in a unit time, such as the kilograms of raw material that can be converted per hour per cubic meter of catalyst per hour. Because the action of a solid catalyst is a surface phenomenon, the catalytic activity is related to the size of the specific surface area of the solid, the nature of the active center on the surface, and the number of active centers per unit surface area. In order to describe the difference in the catalytic activity of different substances, the number of raw materials that can be converted by the catalyst per unit surface area in a unit time is often called the specific activity; the number of molecules converted by each active center in 1 second is called the turnover Or conversions.

Catalytic activity

The catalytic activity of a substance for a specific reaction is related to the reaction conditions, such as the concentration of the reactants and the reaction temperature, so the reaction rate constant and activation energy in the reaction rate equation are also commonly used to characterize the activity of the catalyst. Generally, highly active catalysts exhibit catalytic activity at lower temperatures. Some substances can exhibit catalytic activity at very low concentrations or small specific surface areas. For example, the walls of some metal material containers may also have a catalytic effect on the stored substances. However, the commonly used industrial catalysts are mostly materials with a large specific surface area. For example, nickel blocks do not show obvious catalytic activity for the hydrogenation of fats and oils to hardened oils.

Catalysis is a reaction in which the activation energy of a reactant is changed by a catalyst, the chemical reaction rate of the reactant is changed, and the amount and quality of the catalyst are not changed before and after the reaction.

For a chemical reactant to undergo a chemical reaction, its chemical bond must be changed. Changing or breaking the chemical bond requires a certain amount of energy support. The minimum energy threshold required to change the chemical bond is called activation energy, and the catalyst reduces the chemical reactant by The activation energy makes the chemical reaction easier to proceed, and greatly increases the reaction rate.

It turned out to be an extremely generalized non-special term applicable to the functional activities of advanced living systems and physiological institutions, starting from the activity of solution ions and the activity of enzymes. Activity originally originated only from the word function or action, but was redefined as specific cases before being applied as a specific term. It can be roughly divided into two cases: (1) Corresponding to resting or inactivity, this word is used only in a qualitative sense; (2) as a measure of the intensity of activity Use this word when defining. For giving meaning to the activity, activation or activation is generally used; when the activity is removed, the terms inactivation or inactivation are used. The reactivity of excitatory membranes in stimulating physiology is considered to be an active and discontinuous response not limited to simply passive depolarization accompanied by a certain structural transformation. This term is also used Come call it.

Activity refers to the nature of an activity that has vitality and can survive tenaciously.