Hydrogenation of carbon dioxide to formic acid

Hydrogenation of carbon dioxide to formic acid

NiB amorphous alloy nanoparticles are deposited on In2O3. This novel composite catalysis (NiB/In2O3) realizes the efficient hydrogenation of carbon dioxide to formic acid under irradiation.

Formic acid (HCOOH, MOLECULAR formula CH2O2, molecular weight 46.03), common name formic acid. A colorless liquid with a pungent odor. Weak electrolyte, melting point 8.6℃, boiling point 100.8℃. Formic acid is one of the basic organic chemical raw materials, widely used in pesticide, leather, dye, medicine and rubber industries. Formic acid can be directly used in fabric processing, tanning, textile printing and dyeing and green feed storage, as well as metal surface treatment agents, rubber additives and industrial solvents. It can be used to synthesize various formate esters, acridine dyes and formamide series medical intermediates in organic synthesis. Because carbon dioxide is a linear molecule and very stable, its conversion is difficult. The problems of low efficiency and easy deactivation of catalysts in pure metal catalysis and photocatalytic carbon dioxide conversion limit their application. The development of new composite materials to improve the synergy between photocatalysis and metal catalysis is an effective way to achieve high activity, high selectivity and long-term conversion of carbon dioxide.

The photocatalyst In2O3 has good visible light absorption ability and rich hydroxyl groups on the surface can promote the adsorption of carbon dioxide molecules, which has attracted extensive attention in the aspect of photocatalytic reduction of carbon dioxide. Some precious metals, such as Pt, Pd and Ru, deposited on In2O3, can be used as thermal catalysts and cocatalysts to promote photocatalytic reactions, but precious metals are expensive and scarce. Transition metals such as Ni and Co can replace precious metals, but the key problem is to improve their activity and selectivity.

NiB amorphous alloy and In2O3 semiconductor were combined to develop a new multifunctional catalyst, which showed high formic acid yield (5158.0 umol G-1 H-1) in the photocatalytic hydrogenation of carbon dioxide. In2O3 as a photocatalyst to generate photoelectrons for the activation of carbon dioxide, and provide enough surface hydroxyl (IN-OH), conducive to the adsorption of carbon dioxide In the reaction process; The unique amorphous structure of NiB makes the Ni site electron-rich and promotes the dissociation of hydrogen. NiB nanoparticles are highly dispersed on the surface of In2O3, and provide a rich interface between NiB and In2O3 through interaction with In2O3, which not only promotes photoelectron transfer, reduces photoelectron-hole recombination, but also improves the surface chemical reaction activity, the synergistic effect of photocatalyst and metal catalyst. Achieve efficient hydrogenation of carbon dioxide to produce formic acid.

The total capacity of domestic formic acid plant is about 550,000 tons, accounting for 40% of the global total capacity. Mainly distributed in Shandong, Jiangsu and other places, with Luxi,Acid, Yangtze BASF, Chuandong chemical as the main manufacturers. Among them, 200,000 tons from Luxi, 150,000 tons designed by Shandong acid Chemical Company and 50,000 tons from Nanjing Yangtze BASF Petrochemical.