Related Experiment Video
Updated: Aug 7, 2026

Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
Theoretical study on the reaction mechanism of the gas-phase H2/CO2/Ni(3D) system
Song Qin1, Changwei Hu, Huaqing Yang
1Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China.
Abstract:
The ground-state potential energy surface (PES) in the gas-phase H2/CO2/Ni(3D) system is investigated at the CCSD(T)//B3LYP/6-311+G(2d,2p) levels in order to explore the possible reaction mechanism of the reverse water gas shift reaction catalyzed by Ni(3D). The calculations predict that the C-O bond cleavage of CO2 assisted by co-interacted H2 is prior to the dissociation of the H2, and the most feasible reaction path for Ni(3D) + H2 + CO2 --> Ni(3D) + H2O + CO is endothermic by 12.5 kJ mol(-1) with an energy barrier of 103.9 kJ mol(-1). The rate-determining step for the overall reaction is predicted to be the hydrogen migration with water formation. The promotion effect of H2 on the cleavage of C-O bond in CO2 is also discussed and compared with the analogous reaction of Ni(3D) + CO2 --> NiO + CO, and the difference between triplet and singlet H2/CO2/Ni systems is also discussed.
Related Concept Videos
Catalysis
Multi-Step Reactions
Chemical Stoichiometry and Gases: Using Ideal Gas Law to Determine Moles
Heterogeneous Catalysis
Reaction Mechanisms
For instance, the decomposition of ozone appears to follow a mechanism with two steps:
Rate-Determining Steps
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...

