In the field of catalysis, nanocatalysts, with their ultra-high specific surface area, unique electronic structure, and excellent catalytic activity, have become core materials driving industrial upgrading in energy conversion, environmental protection, and fine chemicals. The synthesis process of nanocatalysts directly determines their structural morphology, particle size distribution, and catalytic performance; therefore, developing efficient, green, and controllable synthesis methods has always been a research hotspot in this field.
Currently, the synthesis methods for nanocatalysts are showing diversified development, mainly divided into two categories: chemical synthesis and physical synthesis. Chemical synthesis methods, due to their simplicity and strong controllability, have become the most widely used synthesis route, with the sol-gel method, hydrothermal/solvothermal method, and reduction method being the most typical. The sol-gel method forms a sol through the hydrolysis and condensation reaction of the precursor, which is then gelled, dried, and calcined to obtain the nanocatalyst. This method can precisely control the chemical composition and pore structure of the product and is suitable for preparing metal oxide nanocatalysts. Hydrothermal/solvothermal methods utilize the high temperature and pressure environment within a closed reactor to promote the dissolution and crystallization of reactants, producing nanoparticles with regular morphology and good dispersion, particularly suitable for synthesizing temperature-sensitive noble metal nanocatalysts. Reduction methods use reducing agents to reduce metal ions into elemental nanoparticles, often combined with surface modification techniques to improve catalyst stability and cycle life.
Physical synthesis methods, while offering advantages in product purity and morphological uniformity, have a relatively narrow application range due to higher equipment costs. These mainly include vapor deposition and laser ablation. Vapor deposition involves the decomposition or chemical reaction of gaseous precursors to deposit a nanocatalytic layer on a support surface, suitable for preparing supported nanocatalysts. Laser ablation uses high-intensity laser bombardment of a target material, causing the deposition of target atoms or ions to form nanoparticles; this method effectively avoids the introduction of chemical impurities.
During the synthesis of nanocatalysts, parameters such as reaction temperature, pH value, precursor concentration, and surfactant type all significantly affect product performance. For example, lower reaction temperatures tend to form smaller nanoparticles, but may lead to insufficient crystallinity; suitable surfactants can effectively inhibit particle aggregation and improve dispersibility. Furthermore, the integration of green synthesis concepts has become a development trend, reducing the environmental impact of the synthesis process by using bio-templates and renewable raw materials.
With continuous breakthroughs in synthesis technology, the performance of nanocatalysts will be further improved, and their application scenarios will continue to expand. In the future, developing nanocatalyst synthesis technologies that combine high activity, high stability, and low cost to achieve efficient transformation from laboratory research to industrial applications will be the core development direction in this field, providing crucial support for promoting clean energy utilization and ecological environmental protection.
