Principles of Core Catalytic Technologies
Catalytic technology alters reaction pathways and lowers activation energy through the use of catalysts. This significantly accelerates reaction rates without changing the overall Gibbs free energy of the reaction or the catalyst's own mass and chemical properties. Mainstream technology types include:
Homogeneous catalysis: The catalyst and reactants exist in the same phase, offering uniform active sites and high selectivity, though catalyst recovery is difficult; typical examples include acid-base catalysis and coordination complex catalysis.
Heterogeneous catalysis: Reactions occur at solid-gas or solid-liquid interfaces. This is the most widely used type in industrial applications, where reactants are adsorbed and activated by active sites on the surface of a solid porous support, making it suitable for continuous industrial production.
Novel frontier catalysis: Includes single-atom catalysis, photocatalysis, electrocatalysis, and nanoconfined catalysis. Notably, single-atom catalysts can achieve catalytic activity up to 5.3 times that of traditional materials, vastly improving metal atom utilization efficiency.
Mainstream Preparation Technologies
Industrial catalysts typically consist of three components: active components, supports, and promoters. Core preparation processes include:
Precipitation method: Active components are precipitated via chemical reactions and subsequently dried and calcined to yield the final product; this method is suitable for preparing multi-component composite oxide catalysts.
Impregnation method: A porous support is immersed in a solution containing active components, allowing the components to be deposited within the support's pores; this is the standard process for preparing supported noble metal catalysts.
Sol-gel method: Achieves molecular-level uniform dispersion of active components within the support, allowing for precise control over key physical parameters such as pore volume and pore size distribution.
Mechanochemical synthesis: Components are mixed uniformly through mechanical ball milling; this process is simple and environmentally friendly, and is commonly used to prepare mesoporous hydrogenation catalysts.
