Infrared spectroscopy at high pressure: adsorption of dinitrogen on supported rhodium in the absence of carbon monoxide

CO- and N2-FTIR characterisation of oxidised Rh species supported on Ce0.68Zr0.32O2

“…8, the band at 2330-2335 cm À1 is assigned to N 2 physisorbed on the support. [37][38][39]63 On Rh(0.71)/SiO 2 , the broad band observed at 2211 cm À1 (Fig. 8a, spectrum i) is ascribed to N 2 bonded to Rh 0 atoms.…”

“…This technique has, however, been scarcely applied to CeO 2 -supported Rh catalysts 12,[28][29][30][31][32] but not to CeZrO 2 -supported ones at all. N 2 -FTIR, which is intrinsically much less sensitive and technically more demanding than CO-FTIR, has only been utilised a few times for the characterisation of zeolite-, 33,34 silica- 35,36 and alumina- [36][37][38][39]20,24 supported Rh catalysts, but not, to our knowledge, for ceria-based Rh catalyst. Thus, it appeared relevant to combine these FTIR probe molecules to characterise the nature of the Rh species supported on CZ.…”

Infrared spectroscopy above atmospheric pressure: support effects on the adsorption of dinitrogen on rhodium

“…2 The work led to infrared observable N2/Rh/A1203 and H/Rh/A1203 surface species at ambient temperature. A new high-pressure infrared cell reactor was used in conjunction with transmission FTIR spectroscopy to investigate the interactions of Rh/Al2O3 films with high-pressure dinitrogen,'V2 dihydr~gen,~ dioxygen: and carbon m~noxide.~ A primary limitation of such high-pressure studies is competitive adsorption of small amounts of impurity species such as CO present in the gases employed which adsorb strongly to the supported metal and/or have high oscillator strengths.l However, it was shown that this limitation could be circumvented by utilizing a Rh/A1203 catalytic converter in the high-pressure manifold.…”

A Cocatalyst that Stabilizes a Hydride Intermediate during Photocatalytic Hydrogen Evolution over a Rhodium‐Doped TiO2 Nanosheet

“…After H 2 treatment, the peak intensity of the O À Hs tretching vibration increased, and apeak assigned to the Rh À Hb ond appeared at 2016 cm À1 . [15] TheF TIR spectra taking the vacuum one as background is shown in the Supporting Information, Figure S7. These results are consistent with the DFT calculations.w hen the hydrogen atom (Z(H) = 1) in Rh À Hb ond is changed to ad euterium atom (Z(D) = 2), the wavenumber of the absorption maxima for O À H(D) and Rh À H(D) stretching vibrations are expected to shift from 3400 to 2473 cm À1 ,a nd from 2016 to 1432 cm À1 , respectively.After D 2 treatment, the peak intensities at 2500 and 1440 cm À1 for the OÀDa nd RhÀDs tretching vibrations increased, as shown in Figure 3b.Therefore,Rh ÀHbonds are present on the surface of the nanosheets.I nt he case of nondoped TiO 2 sheet, the spectra were not changed by H 2 or D 2 treatment (Figure 3c).…”