Mechanistic study of hydrazine decomposition on Ir(111)

Abstract

Theory–experiment evidence of continuous hydrogen generation upon N–N splitting and NH2 assisted dehydrogenation of N2H4 catalysed by metallic Ir(111) catalyst.

Kinetic and mechanistic analysis of NH3decomposition on Ru(0001), Ru(111) and Ir(111) surfaces

“…Ru(0001) has similar catalytic behavior to Ru(111): aer a relatively slow evolution, the H 2 production increases dramatically from 700 K and reaches a plateau at around 900 K. However, the H 2 production on Ru(111) takes place at 400 K, while on Ru(0001), it is at 425 K. Our simulation results suggest that ammonia dissociates on Ir(111) at above 500 K. These results are consistent with the low-and hightemperature proles for the decomposition of hydrazine (N 2 H 4 ) on Ir(111), i.e. at temperatures below 500 K, the products of hydrazine decomposition are mainly NH 3 and N 2 ; however, NH 3 , N 2 and H 2 are observed above 500 K. 73,74 We also made a comparison between experimental and simulated ammonia conversion on Ru catalysts, Fig. 10.…”

Role of defects in carbon materials during metal-free formic acid dehydrogenation

“…49 All the calculations include the long-range dispersion correction approach by Grimme, 50,51 which is an improvement on pure DFT to evaluate molecular interactions. [52][53][54][55] We included also the implicit solvation model as implemented in VASPsol describing the bulk water effect of electrostatics, cavitation, and dispersion on the FA interaction with the C-materials. 56,57 The optimization thresholds were 10 −5 eV and 0.01 eV/Å for electronic and ionic forces relaxation, respectively.…”

Selective decomposition of hydrazine over metal free carbonaceous materials

“…4 that the resulting stability increases following the sequence a-SL o cB-N o cB-H. Zheng et al investigated the same adsorption process on metalfree SiC 3 siligraphene resulting in the following stability sequence: cis-N 2 H 4 o gauche-N 2 H 4 o anti-N 2 H 4 . 65 In addition, mechanistic studies performed on metal surfaces, such as Ir, 95 Cu, 96 Ni [97][98][99] and Pt, 100 are consistent with the siligraphene trends.…”

“…70 All the calculations include the long-range dispersion correction approach by Grimme-DFT-D3 methods, 73,74 an improvement on pure DFT to evaluate molecular interactions. [75][76][77][78] We also included the implicit solvation model as implemented in VASPsol, 79,80 where the solvent is considered as a polarizable continuum dielectric bath. The optimization thresholds for electronic and ionic force relaxation were, respectively, 10 À5 eV and 0.02 eV Å À1 .…”