Catalytic Conversion of Guaiacol Catalyzed by Platinum Supported on Alumina: Reaction Network Including Hydrodeoxygenation Reactions

Abstract

The conversion of guaiacol catalyzed by Pt/γ-Al 2 O 3 in the presence of H 2 was investigated with a flow reactor at 573 K and 140 kPa. Dozens of reaction products were identified, with the most abundant being phenol, catechol, and 3-methylcatechol. The kinetically significant reaction classes were found to be hydrogenolysis [including hydrodeoxygenation (HDO)], hydrogenation, and transalkylation. SelectivityÀconversion data were used to determine an approximate quantitative reaction network accounting for the primary products, and a more detailed qualitative network was also inferred. Catalytic HDO was evidenced by the production of anisole and phenol. The HDO selectivity increased with an increasing H 2 partial pressure and a decreasing temperature. Products formed by transalkylation reactions match those produced in the conversion catalyzed by HY zeolite, in which no deoxygenated products were observed.

Hydropyrolysis of Lignin Using Pd/HZSM-5

“…Gallium performed decarbonylation and aromatization reactions while the zeolite was responsible for oligomerization and cracking reactions. Reaction This is consistent with the previous observation that HDO reactions were strongly dependent on H 2 partial pressure [28]. Their results with both phenolic monomers and dimers are shown in bonds.…”

“…Bifunctional catalysts with PGM have been tested on a variety of supports such as silicates [15], [27], aluminates [8], [28], [29], and carbon-based structures [30]- [32].…”

“…were catalyzed by platinum metal while alumina was responsible for transalkylation reactions [28]. The degree of overall HDO was also determined to be highly dependent on the partial pressure of hydrogen.…”

“…It was observed, for heterogeneous poplar, that the phenolic fraction increased with the addition of Pd to the zeolitic framework by promoting thermal cracking reactions. It is hypothesized that full conversion of phenolics and other oxygenated compounds to naphthenes and paraffins were not achieved due to steady catalyst deactivation over time and the lack of hydrogen partial pressure, resulting in limited hydrodeoxygenation [28]. Marked improvements in decarbonylation and hydrotreating were observed by the increase in monomeric phenol and decrease in aldehydes.…”

High Selectively Catalytic Conversion of Lignin-Based Phenols into para-/m-Xylene over Pt/HZSM-5

“…of methanol other than methylation, co-catalytic conversion of m-cresol with methanol at the C/M ratio of 1/4 was carried out under N 2 . Under these conditions, HDO reactions of m-cresol and xylenols to form toluene and xylenes do not take place [41]. Thus, the observed alkanes, and aromatics (benzene, toluene, p-/m-xylene, o-xylene, and polyalkylated benzenes) under N 2 (see Table 1), may be products from MTA and MTH processes.…”