What is the Production Process of Hopcalite Catalyst?

1. Raw Materials and Production Process

The raw materials for hopcalite catalyst production mainly include copper nitrate, manganese nitrate (providing the active component), and sodium carbonate (precipitant). Activated carbon powder is added as a carrier in some processes. The specific process is as follows:
Raw Material Dissolution and Mixing: Dissolve copper nitrate and manganese nitrate in deionized water according to the appropriate ratio and stir until completely dissolved to form a uniform metal salt solution. If a carrier is required, add activated carbon powder at this stage and stir to disperse.
Precipitation Reaction: While stirring, slowly add sodium carbonate solution. Control the reaction temperature between 60-80°C and the pH between 7-8 to precipitate the metal ions into hydroxides or carbonates, ensuring complete precipitation.
Filtration and Washing: After precipitation, separate the solid and liquid by vacuum filtration. Wash the filter cake several times with deionized water to remove residual sodium ions and other impurities (check the pH of the washing solution until it reaches neutral).
Drying and Calcination: Dry the filter cake at 100-120°C for 4-6 hours to remove moisture. Then, transfer the filter cake to a muffle furnace and calcine it in air at 350-500°C for 3-5 hours to decompose the precipitate into CuO and MnO₂ composite oxides. Molding Processing: The calcined powder is crushed and sieved, then pressed or extruded into granules (typically 3-5mm in diameter) to produce the final hopcalite catalyst.

II. Precautions During the Production Process

Raw Material Purity Control: Copper nitrate and manganese nitrate must be ≥99% pure to avoid impurities such as iron and lead that may affect catalytic activity. The resistivity of deionized water must be ≥10 MΩ·cm to prevent ionic contamination.
Reaction Condition Precision: A pH value that deviates from 7-8 during the precipitation stage can result in incomplete precipitation or residual impurities. Excessively high calcination temperatures can cause sintering of the active components, while excessively low temperatures can lead to incomplete decomposition. Therefore, the furnace temperature must be strictly monitored.
Safety Precautions: Nitrates are corrosive; acid- and alkali-resistant gloves must be worn during handling. Maintain good ventilation during the calcination process to avoid inhalation of dust.

III. Finished Product Storage Methods

Hopcalite catalysts are prone to moisture absorption and agglomeration, which can affect their activity. Storage precautions include:
Sealed in aluminum foil vacuum bags, then enclosed in moisture-proof cardboard boxes to prevent direct contact with air;
Store in a dry, ventilated warehouse with a humidity ≤ 30% and a temperature controlled between 5-30°C;
Keep away from acidic substances and reducing gases (such as hydrogen sulfide) to prevent corrosion or reduction of the active components.

The production of hopcalite catalysts requires careful consideration of raw material ratios, reaction conditions, and the molding process. Strict control of each step ensures efficient carbon monoxide conversion. Proper storage can extend their service life and ensure their effectiveness.

author: Hazel
date: 2025-10-10