Recently, Wang Xiaodong, a researcher at the Center for Catalysis and New Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and a research team from North Carolina State University have made progress in chemical chain ammonia oxidation to nitric oxide, and proposed a chemical chain based technology.
A new process of ammonia oxidation to nitric oxide
Since the early twentieth century, the Ostwald Process for the selective oxidation of ammonia gas to nitric oxide using platinum group metal alloys as catalysts has been considered the industry standard for the production of nitric acid
However, this process has high reaction temperature (800-950 °C), severe catalyst loss, and is the largest industrial emission of the greenhouse gas N2O
Therefore, the development of low-cost and high-efficiency catalysts and green ammonia oxidation processes have received extensive attention
In this work, the research team used non-precious metal V 2 O 5 as a catalyst to oxidize ammonia to nitric oxide under relatively mild conditions (650 °C), and the process showed excellent ammonia selective oxidation performance
Compared with the traditional Ostwald process, the ammonia oxidation process based on chemical chain technology has the following advantages: chemical chain ammonia oxidation is divided into two steps of reduction and oxidation, which is beneficial to precisely control the residence time of NH3 and the reduction degree of oxide catalysts.
and the ratio of catalyst surface active species NHx to lattice oxygen; the reduced catalyst can be oxidatively regenerated, which is beneficial to inhibit catalyst deactivation; the use of lattice oxygen instead of non-selective gas-phase oxygen is beneficial to inhibit N 2 O generation; traditional ammonia In the oxidation process, air is used as the oxidant, and the gas product contains a large amount of inert gas N 2 (about 3/4 of the total gas flow).
The chemical chain ammonia oxidation uses the lattice oxygen of the metal oxide catalyst as the oxidant .
To achieve NH 3 oxidation process enhancement