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Recently, the team led by Professor Zeng Jie from Anhui University of Technology, in collaboration with the team led by Fanli Chun from Toyama University in Japan, developed a new type of \"metal oxide-molecular sieve\" composite catalyst. By utilizing a multi-step sequential catalytic process, they succeeded in directly synthesizing p-xylene from carbon dioxide and hydrogen, achieving a world record for space-time yield per reaction step. On June 10th, Beijing time, this research finding was published in the international academic journal Journal of the American Chemical Society. p-Xylene is a key raw material for producing chemical products such as polyester fibers. Currently, the common method for industrially synthesizing p-xylene is based on the catalytic reforming of heavy oil; approximately 4 tons of oil are consumed to produce 1 ton of p-xylene, with around 3 tons of carbon dioxide being emitted in the process. Using renewable energy to electrolyze water to produce hydrogen, which is then reacted with carbon dioxide to directly manufacture p-xylene, holds promise for enabling the resourceful utilization of greenhouse gas carbon dioxide, while offering an alternative to traditional production processes that are highly energy-intensive and emit large amounts of pollutants. It is understood that the composite catalyst developed by the research team consists mainly of two modules. Among them, the metal oxide module is responsible for catalyzing the hydrogenation of carbon dioxide to produce short-chain alkenes, while the molecular sieve module facilitates the polymerization, cyclization, and aromatization of these short-chain alkenes, ultimately yielding p-xylene. To improve the selectivity for p-xylene, the research team carried out a meticulous design to \"encapsulate\" the molecular sieve modules. Its internal hollow structure can effectively promote the mass transfer of intermediates. At the same time, the pore size of the molecular sieve matches the size of p-xylene molecules, allowing it to specifically facilitate the diffusion of p-xylene products from the inside outward. Furthermore, the research team also passivated the outer surface of the \"capsules\" to prevent further side reactions such as isomerization and alkylation of the produced p-xylene. Thanks to this unique design, the research team has managed to raise the space-time yield for p-xylene to a new level; using 1000 grams of the composite catalyst, 1000.8 grams of p-xylene can be produced in just one day, which far exceeds the performance levels reported in existing scientific literature. The researchers say that the composite catalyst design they proposed could also be applied to other carbon dioxide hydrogenation reaction systems, thereby enabling the \"tailored\" adjustment of the carbon chain length and molecular size of high-value-added products.