Heterogeneous catalysts, also known as heterogeneous catalysts, are used in reactions involving different phases, meaning the reactants and the catalysts are in different states. For example, in the production of margarine, solid nickel (the catalyst) can convert unsaturated vegetable oil and hydrogen into saturated fat. Solid nickel is a heterogeneous catalyst, and the reactants it catalyzes are liquid (vegetable oil) and gaseous (hydrogen). A simple heterogeneous catalytic reaction involves the adsorption of reactants (or substrates) onto the catalyst surface, the breaking of bonds within the reactants leading to the formation of new bonds, and the detachment of products from the reaction sites due to the weak bonds between the products and the catalyst. Many different structures of catalyst surfaces are known for adsorption and reaction.
Biocatalysts are organic compounds (mostly proteins, but a small amount of RNA also has biocatalytic function) produced by plants, animals, and microorganisms, formerly known as enzymes. Enzymatic catalysis also exhibits selectivity. For example, starch. Enzymes catalyze the hydrolysis of starch into dextrin and maltose, and proteases catalyze the hydrolysis of proteins into peptides, etc. Living organisms use enzymes to accelerate chemical reactions within their bodies. Without enzymes, many chemical reactions would proceed very slowly, making it difficult to sustain life. Enzymes function optimally at around 37°C (human body temperature). If the temperature exceeds 50°C or 60°C, enzymes are destroyed and cease to function. Therefore, biological detergents that use enzymes to break down stains on clothing are most effective when used at low temperatures. Enzymes have significant applications in physiology, medicine, agriculture, and industry. Currently, the application of enzyme preparations is becoming increasingly widespread.
