How to accurately categorize catalysts

Classification and import of catalysts
Speaking of “catalyst”, most people will recall those distant terms in secondary school chemistry textbooks. As a matter of fact, catalyst is closely related to our daily life, and it is an important medium for the production of many chemical products, which can be regarded as the cornerstone of chemical industry, and also known as the “chip” in the field of chemical industry. Below, I will take you to understand the import of catalyst.

What is catalyst
According to the definition of the International Union of Pure and Applied Chemistry (IUPAC), a catalyst refers to a substance that increases the rate of a reaction without changing the total standard Gibbs free energy change of the reaction. This action is called catalysis and reactions involving catalysts are called catalytic reactions. A catalyst keeps its own mass and chemical properties unchanged during a chemical reaction and is therefore also known as a catalyst. This means that catalysts do not introduce new energy inputs into the reaction system, but rather speed up the reaction process by lowering the activation energy of the reactants or in other ways, and they can facilitate a chemical reaction without altering the reaction temperature, allowing the chemical reaction to take place at a lower temperature.
There are many types of catalysts
①By state: divided into liquid catalyst and solid catalyst.
② According to the phase of the reaction system: divided into homogeneous catalysts and multiphase catalysts, homogeneous catalysts are acid, alkali, soluble transition metal compounds and peroxide catalysts; multiphase catalysts are solid acid catalysts, organic alkali catalysts, metal catalysts, metal oxides catalysts, complex catalysts, rare-earth catalysts, molecular sieve catalysts, biocatalysts, nanometer catalysts and so on.
(iii) According to the type of reaction: polymerization, polycondensation, esterification, acetalization, hydrogenation, dehydrogenation, oxidation, reduction, alkylation, isomerization and other catalysts.
(iv) According to the size of the role: the main catalyst and co-catalyst.

Wide range of catalyst applications
Catalysts are widely used in petrochemical, biochemical, environmental protection and other fields, petroleum refining and the development of chemical technology are inseparable from catalysts. At present, environmental protection catalysts, chemical catalysts and petroleum refining catalysts are listed as the three major fields of the catalyst industry, with chemical synthesis, petrochemical refining, and environmental treatment as its three main application scenarios. Catalysts are widely used in all walks of life around the world and have great prospects for development. In short, catalysts and their development are indispensable to the survival and development of human beings, as well as to food, clothing, housing and transportation.
Classification of Catalysts
According to the “Notes on Commodities and Items under the Import and Export Tariffs (2022)”, catalysts under item 38.15 “Reaction initiators, reaction promoters, catalysts, not elsewhere listed in other headings” include preparations that cause or promote certain chemical reactions, and products that prevent chemical reactions are not categorized under this heading.
They are divided into the following two categories
The first category consists mainly of one or more active substances deposited on a carrier (called “carrier catalysts”) or a mixture based on active substances. In most cases, these active substances are certain metals, metal oxides, other metal compounds and mixtures thereof. Metals often used alone or in compound form are cobalt, nickel, palladium, platinum, molybdenum, chromium, copper or zinc. The carrier (which may sometimes be activated) is usually composed of vanadinite, carbon, silica gel, silica fossil powder, or ceramic material. Carrier catalysts include Ziegler catalysts and Ziegler-Natta type catalysts.
The second group consists of mixtures of certain compounds as basic ingredients, which vary in nature and proportion according to the different catalytic chemical reactions. These include: free radical “catalysts”, ionic “catalysts”, “polycondensation catalysts”. The second group of agents is typically used in the preparation of polymers.
Item 38.15 does not include
1. Spent catalysts used for the extraction of base metals or the preparation of base metal compounds (item 26.20) and spent catalysts used primarily for the recovery of precious metals (item 71.12);
2. individual compounds for which chemical definitions already exist (Chapter XXVIII or XXIX)
3. catalysts of pure metal or alloys of pure metal in the form of fine powders or screen fabrics, etc. (Class XIV or XV)
4. formulated rubber accelerators for the vulcanization of rubber (Item 38.12).
Import Declaration Precautions
In order to promote trade facilitation and speed up customs clearance, the consignee or consignor of imported or exported goods, or their agents, when filling in the customs declaration for imported or exported goods, should fill in the declaration in accordance with the content of the elements of declaration for the commodities listed in the “People’s Republic of China Customs Import and Export Commodity Specification Declaration Catalogue and Interpretation (2024)”.
When importing catalysts under tariff heading 38.15, the categorization elements of the normative declaration include:

Product name;
Use (e.g. to promote the polymerization of a certain polymer, etc.);
Ingredient content.
Price elements include:
1. Brand (Chinese or foreign name);

2. Model.
When enterprises declare, they should also pay attention to the following standardized declaration elements: when declaring the “content of ingredients”, they should truthfully declare the types of substances contained in the goods and their contents, especially the contents of platinum, rhodium, palladium and other precious metals; the “content” is expressed as a percentage.
At the same time, if there are royalties paid in the form of non-trade remittances related to the imported catalysts and constituting the conditions for the sale of the goods to the People’s Republic of China, it is also necessary to incorporate the corresponding royalties into the duty-paid price of the imported catalysts through the apportionment of the royalties.