Structure and surface characteristics of Fe-promoted Ni/Al₂O₃ catalysts for hydrogenation of 1,4-butynediol to 1,4-butenediol in a slurry-bed reactor

Abstract

Nanostructured Ni–xFe/Al2O3 catalysts prepared by sol–gel combustion synthesis (SGC) display superior activity in hydrogenation of 1,4-butynediol to 1,4-butenediol. The Fe addition promoted the Ni reducibility and stabilized the Al2O3 structure.

Heteroatom Promoted Ni/Al2O3 Catalysts for Highly Efficient Hydrogenation of 1,4‐Butynediol to 1,4‐Butenediol

“…The effects of Ce, Ag, Mo, Fe, and Co, on the textural characteristic of Ni/Al 2 O 3 catalysts are studied by using the nitrogen adsorption/desorption technique (Figure ). According to the classification of IUPAC, nitrogen isotherms of all the samples exhibit type IV isotherms . The nitrogen adsorption‐desorption isotherms of all samples exhibit a comparable H2 hysteresis loop with a saturated adsorption platform, which reflects the relatively uniform distribution of pore diameter and existence of mesopores.…”

“…The as‐prepared Ni−M/Al 2 O 3 displays the diffraction peaks at 37.2°, 43.3°, 62.9° and 76.9°, which could be assigned to the NiO (JPCDS 73‐1519). Additional diffraction peaks at 45.0° and 65.6° are indexed to the spinel NiAl 2 O 4 (JCPDS 10‐0339) . It could be observed that the intensity of NiO peaks weakens after the introduction of promoters, indicating the presence of interactions between promoters and nickel or the increased coverage of crystallites of the promoters species.…”

“…It could be observed that the intensity of NiO peaks weakens after the introduction of promoters, indicating the presence of interactions between promoters and nickel or the increased coverage of crystallites of the promoters species. The XRD results reveal that there are no detectable diffraction peaks of the promoters in the case of promoters loaded catalysts, possibly due to the amorphous state of the added promoters or its existence in a highly dispersed form being interacted with the alumina support surface . Figure b shows the XRD patterns of the Ni‐based catalysts reduced at 923 K for 3 h. All catalysts exhibit peaks at 44.3°, 51.8°, and 76.3°, which correspond to metallic Ni with a face‐centered cubic structure (JCPDS, No.87‐0712) .…”

“…H 2 temperature‐programmed reduction (H 2 ‐TPR) technique permits not only to characterize the metal‐support interactions but also to elucidate the role of promoters in the reduction process and the influence of one or more component systems . Figure shows the H 2 −TPR profiles of Ni/Al 2 O 3 and Ni−M/Al 2 O 3 (M=Ce, Ag, Mo, Fe, and Co), in which the overlapped peaks are deconvolved using Gaussian‐type functions.…”

“…Nickel‐based catalysts have attracted increased attention due to their relatively low cost and high intrinsic activities . It was already reported that Ni supported catalysts can be used with the desired catalytic properties (e. g. activity, selectivity, and stability) during the hydrogenation process, which is superior in comparison with the Raney nickel catalysts …”