Intermetallic PdZn/TiO2 catalysts for methanol production from CO2 hydrogenation: The effect of ZnO loading on PdZn-ZnO sites and its influence on activity

Enhanced Photocurrent and Photocatalytic Performance of a π-Conjugated Polymer Hybridized with Hexagonal ZnO Nanotubes

“…A local area was selected for magnification to obtain the lattice fringes of ZnO. As shown in Figure b, 0.248 nm corresponds to the (101) crystal plane of ZnO, while 0.261 and 0.282 nm correspond to the (002) crystal plane and (100) crystal plane of ZnO, respectively . At the same time, in the lattice stripe of ZnO, it can be detected that the (100) crystal plane and (002) crystal plane of ZnO have an included angle of 120°, which belongs to the typical hexagonal crystal system and is consistent with the results of XRD.…”

“…As shown in Figure 3b, 0.248 nm corresponds to the (101) crystal plane of ZnO, while 0.261 and 0.282 nm correspond to the (002) crystal plane and (100) crystal plane of ZnO, respectively. 22 At the same time, in the lattice stripe of ZnO, it can be detected that the (100) crystal plane and (002) crystal plane of ZnO have an included angle of 120°, which belongs to the typical hexagonal crystal system and is consistent with the results of XRD. In the TEM images of ZnO/SPI (Figure 3b), it is evident that ZnO nanotubes are dispersed in the stacked SPI with clear boundaries.…”

Intermetallic Palladium–Zinc Nanoparticles for the Ultraselective Hydrogenative Rearrangement of Furan Compounds

“…These results suggest that Pd-based catalysts can easily activate H 2 and that CO adsorption is the rate-determining step during hydrogenation. Meanwhile, the kinetic isotope experiments showed a lower times (1.22–1.45) of CO hydrogenation rate under the D 2 atmosphere than that under the H 2 atmosphere (Figure S8E,F), which further indicates that the H 2 activation step is rapid and not significantly included in the rate-determining step. , Previous studies have reported that intermetallic catalysts promote selective hydrogenation, such as the CC semihydrogenation of alkynols or acetylene to form enols or olefins, , CC hydrogenation of 1,3-butadiene to 1-butene, hydrogenation of CO 2 to methanol, NO 2 hydrogenation of nitrophenols to aminophenols, and N-methylation of N -methylaniline to N , N -dimethylaniline in organic solvents or solvent-free conditions via surface geometric and electronic effects. Furthermore, reactions conducted in isopropanol and cyclohexane only generated CO hydrogenated MFA with a selectivity of 99.9%; however, the MF conversion rates were <20% (Figure S8I).…”

“…In situ CO adsorption infrared spectroscopy showed clear signals for double bridge-bonded (1954 cm –1 ) and 3-fold-bonded CO (1851 cm –1 ) in Pd/ZnO (Figure S2A). , The two bridge-bonded and 3-fold-bonded CO peaks are typical of pure Pd catalysts. The PdZn/ZnO spectrum showed no CO 3-fold adsorption peak and a weak bridge adsorption peak but included a stronger linear adsorption peak at 2045 cm –1 , indicating that Zn broke the contiguous Pd configuration and isolated its active sites.…”

“… , Inductively coupled plasma-optical emission spectroscopy (ICP-OES) spectra and N 2 adsorption/desorption isotherms showed that Pd/ZnO and PdZn/ZnO possessed similar Pd contents of 4.9–5.4 wt %, with Brunauer–Emmett–Teller (BET) specific surface areas of 9.6–10.7 m 2 ·g –1 (Figure S1B, Table S1). Powder X-ray diffraction (XRD) showed the disappearance of Pd peaks at 40.0° and the appearance of PdZn alloy peaks at 41.1° (Figure A). , Transmission electron microscopy (TEM) showed that the average PdZn nanoparticle size in PdZn/ZnO was 5.5 nm, which was slightly larger than that of the initial Pd nanoparticle seed in Pd/ZnO (5.0 nm) (Figure S1C,E). Meanwhile, two obvious lattice spacings were observed at 0.231 and 0.219 nm, which were consistent with the [111] plane of Pd and PdZn nanoparticles, respectively (Figure S1D,F).…”