Effect of the Support Functionalization of Mono- and Bimetallic Ni/Co Supported on Graphene in Hydrodeoxygenation of Guaiacol

Abstract

Mono- and bimetallic Ni/Co catalysts were prepared over reduced graphene oxide undoped and doped with N and evaluated in the hydrodeoxygenation of guaiacol in a batch reactor. Catalysts were characterized by N2 physisorption, CO chemisorption, XRD, TEM, TPR, and XPS. Results showed that catalytic activity was improved in all the cases by doping with N. Such enhancement was ascribed to electron transfer from the support to the metal particles. In the case of bimetallic catalysts, measured activity was improved, which can be ascribed to a synergistic effect between Ni and Co. Such an effect was stronger over the unmodified graphene than the one modified by N. The product distribution was unaffected by the support but differed from the respective monometallic catalysts suggesting the formation of new active sites.

Ni nanoparticles embedded in nitrogen doped carbon derived from metal–organic frameworks for the efficient hydrogenation of vanillin to vanillyl alcohol

“…8). 37,38 Three peaks at ca. 128 1C, 213 1C and 373 1C were observed for Ni@CN-325, while two major peaks at ca.…”

Cobalt–Graphene Catalyst for Selective Hydrodeoxygenation of Guaiacol to Cyclohexanol

“…The Ni 2.5 /rGO catalyst achieves 90.1 mol% conversion with 62.4 mol% and 35.1 mol% selectivity to CYHAOL and MOCYHOL, respectively. Ni catalysts usually catalyze total HYD to MOCYHOL as a major side reaction, especially at lower reaction temperatures [26]. The Fe 2.5 /GO catalyst only converts 1.8 mol% of GUA.…”

“…On the other hand, some studies have focused on the development of low-cost transition metal catalysts. Some Ni-based catalysts [18][19][20][21][22][23][24][25] and Co-based catalysts [26][27][28] catalyzed HDO of GUA with CYHAOL as the main product. In particular, the production of CYHAOL in more than 90% yield was achieved over several Co-containing catalysts, including Ru-Co supported on active carbon [16], Ni-Co supported carbon nanotubes [25], and Co supported on TiO 2 [27].…”

“…Table S2 lists Co-based catalysts used in HDO of GUA. In addition to forming CY-HAOL [26][27][28], some Co-based catalysts lead to CYHA [8,9], phenol (Ph) [29,30] and benzene [31,32] products. As shown in Table S2, the Co-based catalysts were reduced with H 2 [8,9,26,27,29,30,32], NH 3 [28], or in situ co-pyrolysis with cellulose [31] before use, indicating the reduction treatment of the catalysts was necessary for catalytic activity.…”

“…In addition to forming CY-HAOL [26][27][28], some Co-based catalysts lead to CYHA [8,9], phenol (Ph) [29,30] and benzene [31,32] products. As shown in Table S2, the Co-based catalysts were reduced with H 2 [8,9,26,27,29,30,32], NH 3 [28], or in situ co-pyrolysis with cellulose [31] before use, indicating the reduction treatment of the catalysts was necessary for catalytic activity. For instance, the Co/TiO 2 catalyst without reduction by H 2 generated no propylcyclohexanol production in selective HDO of eugenol [27].…”