The steam reforming of guaiacol for hydrogen via Ni/Al ₂ O ₃ : The influence of dispersion

Abstract

Summary In this paper, three Ni/Al2O3 catalysts with different structure were prepared by different methods. The differences between the catalysts had been compared by H2 temperature program reduction (H2‐TPR), X‐ray diffraction, thermogravimetric analysis, scanning electron microscope, transmission electron microscope, and X‐ray photoelectron spectroscopy. The results showed that synthesis method had significant effect on the combination of Ni particle with carrier. The method of coprecipitation could help to improve the combination of Ni and Al2O3, and the effect was further enhanced after adding polyethylene glycol (PEG). Due to the enhanced interaction between the active metal and the carrier, the NiO could be easily deoxidized and hard to sinter, which could obtain smaller and more dispersed Ni particles. Moreover, the addition of PEG improved the Ni particle size and its dispersion, and promoted the formation of the unique acicular Al2O3. The performance of guaiacol steam catalytic reforming via different catalysts was further analyzed, and the results showed the catalyst obtained by coprecipitation method with PEG exhibited best activity with 73.8% guaiacol conversion and 23.1 wt% H2 yield.

Stability and activity maintenance of Ni catalysts supported on La‐, Ce‐, and Mg‐promoted Al 2 O 3 and ZrO 2 for H 2 production from steam reforming of glycerol

“…Therefore, considerable research has focused on screening suitable supports and promoters for Ni or modifying the catalyst preparation method, trying to overcome these obstacles. Studied carriers for active Ni mainly include single metal oxide such as Al 2 O 3, 6‐11 ZrO 2, 4,8,12 La 2 O 3, 13 CeO 2, 10,14,15 MgO, 8 CaO, 16 SiO 2, 8,10,17 composite oxides such as CeO 2 ‐Al 2 O 3, 18‐23 La 2 O 3 ‐Al 2 O 3, 6,24‐26 MgO‐Al 2 O 3, 27‐31 CaO‐Al 2 O 3, 32 La 2 O 3 ‐ZrO 2, 33,34 CeO 2 ‐ZrO 2, 35‐38 CeO 2 ‐La 2 O 3 ‐Al 2 O 3, 39 and carbon material such as CNT, 30,40,41 activated biochar, 42 and graphene oxide 43,44 . Al 2 O 3 ‐supported Ni catalysts have received the most extensive study as stated above because the porous γ‐Al 2 O 3 with high surface area is very beneficial to form highly dispersed Ni crystals over the catalyst surface, thus achieving a high level of activity for SR reaction 8,10 .…”

Chemical Vapor Deposition Synthesis of Carbon Nanomaterials over Lanthanum-Nickel Co-Loaded Catalyst Supported on Novel Radially Aligned Nano Rutile

“…La-Ni co-loaded catalysts have previously been prepared on different supports, such as alumina and silica. Ni/Al 2 O 3 has been prepared for use in steam reforming of ethanol and phenol [14,15]. However, adding La to form La-Ni/ Al 2 O 3 catalyst stabilized the alumina support and improved the resistance to coking of the Ni/Al 2 O 3 in various steam reforming reactions [16].…”