Modern society is built on a "carbon economy," with a large number of products made from carbon-based materials. As fossil fuels are gradually phased out, the sustainable use of alternative carbon sources in more efficient and environmentally friendly ways, including captured carbon dioxide, alternative CH₄, and biomass, will become increasingly important for the supply of carbon fuels and chemicals in our daily lives. Most chemical processes involve catalysts, which activate the catalysts through different driving forces (such as light, heat, electricity, and plasma) to convert abundant raw materials into demanding chemical products/fuels to meet our daily needs. Among various catalytic reaction systems, thermal and photonic co-catalysis stands out, while exploring the potential of solar energy in chemical synthesis, especially in the CO₂-centered C1 chemical field.
Thermal activation is currently one of the most effective and feasible strategies in industrial chemical synthesis. However, thermal-driven catalytic processes face three common bottlenecks: (1) high temperature and high pressure are the norm, leading to high energy consumption and many side reactions; (2) there is a need to balance thermodynamics and kinetics; (3) catalysts easily deactivate under high-temperature and high-pressure conditions. For example, in methane reforming processes, nickel-based catalysts exposed to 800℃~900℃ and 2 MPa~3 MPa can suffer from deactivation due to coking. Photocatalysis utilizes light energy to initiate and promote chemical reactions, typically conducted at room temperature. Semiconductor-based photocatalysis faces the following challenges: (1) lower reaction efficiency; (2) lower selectivity; (3) low utilization of the solar spectrum. A single driving mode is like "a single tree cannot support a forest," highlighting the urgent need for the "dual sword combination" of light and heat!
Mixed catalytic systems driven by dual activation of light and heat typically utilize the synergistic effect between thermal activation and light induction. The existence of this synergy makes it challenging to understand and study the effects of individual stimuli (light/heat) and the surface processes of catalysts. Xie[1] et al. proposed four modes of photothermal synergy:
Figure 1 Schematic of four categories of photothermal catalysis: from reactants (A+B) to final products (C+D)
No.1 Photothermal Heating Catalytic Reaction
Photothermal heating catalysis: Light energy is directly converted into thermal energy to drive traditional thermal catalytic reactions. Li[2] et al. found that using continuous wave light-emitting diodes to simulate concentrated sunlight can produce ammonia in large quantities without any external heating or pressurization.
No.2 Thermally Enhanced Photocatalysis
Thermally enhanced photocatalysis: Moderate heating improves photocatalytic efficiency. Song[3] et al. achieved high selectivity oxidation of methane to ethane at 200℃ using Au-ZnO/TiO₂, enhancing the activity by 10 times.
Figure 2 Comparison of Ethane Production Yield in a Self-Made Reactor between Thermal Catalysis and Photothermal Catalysis
No.3 Photo-enhanced Thermocatalysis
Photo-enhanced thermocatalysis: Photogenerated carriers "assist" thermal catalytic steps. Phillip Christopher[4] et al. found that Ag nanostructures under light can increase the rate of ethylene epoxidation by three times while reducing energy consumption.
No.4 Photothermal Cascade Catalysis
Photothermal cascade catalysis: Light and heat drive processes stepwise, breaking through thermodynamic limitations. Guan[5] et al. demonstrated that under xenon or mercury lamp irradiation, a Cu/ZnO&Pt-K₂Ti₆O₁₃ composite catalyst can reduce CO₂ to CH₃OH, indicating that simultaneously providing photons and thermal energy can enhance the activity of photocatalysts.
▼
Based on this, Polifly Technology has launched the PLR-RP Series Photothermal Catalytic Reaction Evaluation Device, providing a platform for systematic research on photothermal catalytic reactions. The innovative quartz column light guiding method and reactor design improve the irradiation efficiency of the light source and the light absorption area of the catalyst, meeting the needs of gas-solid phase reactions under photothermal co-catalysis. (Consultation Phone: 400-1161-365)
The photodriven heterogeneous catalysis through mixed photothermal dual activation pathways is a promising direction for achieving clean and sustainable energy and chemical production. Photothermal co-catalysis combines the advantages of photocatalysis and thermal catalysis, featuring high efficiency, high selectivity, mild conditions, and environmental friendliness, making it an important research direction in the fields of green chemistry and sustainable energy. With continuous advancements in materials and reactor design, photothermal co-catalysis is expected to achieve breakthroughs in industrial applications, providing key technological support for carbon neutrality and energy transition.
