Claydon RM, Roman-Ramirez LA, Wood J. Comparative Study on the Hydrogenation of Naphthalene over Both Al
2O
3-Supported Pd and NiMo Catalysts against a Novel LDH-Derived Ni-MMO-Supported Mo Catalyst.
ACS OMEGA 2021;
6:20053-20067. [PMID:
34368590 PMCID:
PMC8340395 DOI:
10.1021/acsomega.1c03083]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Naphthalene hydrogenation was studied over a novel Ni-Al-layered double hydroxide-derived Mo-doped mixed metal oxide (Mo-MMO), contrasted against bifunctional NiMo/Al2O3, and Pd-doped Al2O3 catalysts, the latter of which with Pd loadings of 1, 2, and 5 wt %. Reaction rate constants were derived from a pseudo-first-order kinetic pathway describing a two-step hydrogenation pathway to tetralin (k 1) and decalin (k 2). The Mo-MMO catalyst achieved comparable reaction rates to Pd2%/Al2O3 at double concentration. When using Pd5%/Al2O3, tetralin hydrogenation was favored over naphthalene hydrogenation culminating in a k 2 value of 0.224 compared to a k 1 value of 0.069. Ni- and Mo-based catalysts produced the most significant cis-decalin production, with Mo-MMO culminating at a cis/trans ratio of 0.62 as well as providing enhanced activity in naphthalene hydrogenation compared to NiMo/Al2O3. Consequently, Mo-MMO presents an opportunity to generate more alkyl naphthenes in subsequent hydrodecyclization reactions and therefore a higher cetane number in transport fuels. This is contrasted by a preferential production of trans-decalin observed when using all of the Al2O3-supported Pd catalysts, as a result of octalin intermediate orientations on the catalyst surface as a function of the electronic properties of Pd catalysts.
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