Reactivity of methanol over copper supported on well-shaped CeO₂: a TPD-DRIFTS study

Abstract

Methoxy and formate species resulting from methanol adsorption on Cu supported on well-shaped CeO2 are morphology-dependent.

CO2 Methanation over Rh/CeO2 Studied with Infrared Modulation Excitation Spectroscopy and Phase Sensitive Detection

“…However, in the PSD plots for τ = 120 s, minor peaks at approximately 1550 and 1300 cm −1 can be seen in Figure 3 and the C -H bond vibrations ν(CH) at ∼2850 cm −1 and a combination band of δ(CH)+ν as (OCO) at ∼2950 cm −1 are visible in Figure 4. Together, these could correspond to HCOO at (non-reduced) CeO 2 [18]. The HCOO on the CeO 2−δ seems to occur during all temperatures for the 30 s measurement.…”

“…Interestingly, their amplitudes are significantly higher during hydrogenation conditions compared to those of pure CO 2 adsorption, which signifies that these peaks arise mainly due to hydrogenation products. Based on our AP-XPS data [13] and previous literature assignments [18], these peaks should be, at least in part, due to surface HCOO out of which the bidentate coordination on CeO 2 is the most likely [18]. As such, an initial peak assignment for the steady-state spectra could include the two twin peaks at 1560/1510 and 1373/1327 cm −1 to correspond to two kinds of bidentate HCOO: one that is adsorbed at a non-reduced site (CeO 2 ) giving rise to the pair at 1560(ν as )/1327(ν s ) cm −1 with a high ∆ν as-s of 233 cm −1 and one that is adsorbed at, or in the vicinity of, a reduced site (CeO 2−δ ) resulting in the pair at 1510(ν as )/1373(ν s ) cm −1 with a low ∆ν as-s of 137 cm −1 [18].…”

Recent Advances on the Rational Design of Non-Precious Metal Oxide Catalysts Exemplified by CuOx/CeO2 Binary System: Implications of Size, Shape and Electronic Effects on Intrinsic Reactivity and Metal-Support Interactions

“…However, not all methods lead to particles of well-ordered size and shape with uniform dispersion on the catalyst surface [145]. Among the different methods, the hydrothermal one has attracted considerable attention, due to the simplicity of the precursor compounds used, the short reaction time, the homogeneity in morphology, as well as the acquisition of various nanostructures, such as rods, polyhedra, cubes, wires [107,117,121,124,131,134,135,[146][147][148][149][150][151][152][153][154][155][156][157][158][159]. Ceria nanocrystals have three low-index lattice facets of different activity and stability, namely, {100}, {110}, {111} [48,106], as shown in Figure 6.…”

Studies of adsorption of α,β-unsaturated carbonyl compounds on heterogeneous Au/CeO2, Au/TiO2 and Au/SiO2 catalysts during reduction by hydrogen

“…As the catalyst contains AuNPs facilitating adsorption of hydrogen, different H x CO y species are presumably formed. [43][44][45] Hence, carbon oxides are released from the Au/ CeO 2 surface at higher temperatures as evidenced by peaks shied to 484 C and 805 C.…”