Selective Hydrogenolysis of Dibenzofuran over Highly Efficient Pt/MgO Catalysts to o-Phenylphenol

Abstract

Direct selective hydrogenolysis of dibenzofuran (DBF) derived from coal and shale oil to a value-added chemical, ortho-phenylphenol (OPP), with high selectivity (80%) and yield (48%) has been achieved over Pt/MgO at 400 °C and 1.0 MPa by controlling the C–O bond cleavage as well as minimizing the extent of hydrogenation of aromatic rings. Meanwhile, Pt/SiO2, Pt/Al2O3, and Pt/MgO/Al2O3 catalysts were used for the DBF hydrogenolysis and showed lower selectivity for OPP. The influence of reaction parameters has been studied to unveil the optimal reaction conditions. And the phenomenon of OPP dehydrogenation is found over various catalysts for the hydrogenation reaction of OPP. Extensive reactions and catalyst characterizations demonstrated that the OPP selectivity and the dehydrogenation of OPP to DBF follows the order of supports basicity: MgO-900 > MgO > SiO2 > MgO/Al2O3 > Al2O3, which shows that the acid–base properties of supports impact the adsorption and desorption behaviors of DBF and OPP, and results in the disparity of OPP selectivity and the dehydrogenation of OPP. Finally, a plausible reaction pathway and mechanistic understanding are proposed.

Plasma-catalytic ammonia synthesis beyond thermal equilibrium on Ru-based catalysts in non-thermal plasma

“…Below 175°C, the conversion obtained with Ru/MgO is similar to the conversion with bare MgO, implying that plasma chemistry is the dominant NH 3 formation mechanism at low temperature, rather than any catalytic contribution over the Ru surface. This is in line with the fact that ammonia desorption from Ru/Al 2 O 3 , Ru/SiO 2 , and Ru/AC requires at least 180°C, 38 although weaker adsorption of ammonia on Ru/MgO is suggested by Xie et al 39 and Zhang et al 40 based on TPD experiments, as well as by Szmigiel et al 41 based on temperature programmed reaction experiments with adsorbed N ads with H 2 . In any case, hydrogenation of N or NH X surface species and/or desorption of ammonia limit the reaction at temperatures below 175°C, based on the temperature programmed reaction experiments performed by Szmigiel et al 41 At temperatures above 175°C, the conversion to NH 3 over Ru/MgO increases with increasing temperature.…”

NiMoS on alumina-USY zeolites for hydrotreating lignin dimers: effect of support acidity and cleavage of C–C bonds

“…60 Also, similar product formation was reported for HDO of DBF using a Pt based catalyst over various acid-base supports. [61][62][63][64] For the Y-based catalysts, the dehydration reaction is strongly favoured over DDO resulting in a high yield of DBF which is over 44%, compared to 23% with NiMoA (Table 3). As Fig.…”

Deactivation and Regeneration Study of a Co-Promoted MoO3 Catalyst in Hydrogenolysis of Dibenzofuran

“…Previous works illustrated that conventional hydrotreating catalysts such as transition-metal sulfides − and supported noble-metal and transition-metal catalysts are active for the cleavage of the C–O bond. ,,− However, for the sulfided catalysts, additional sulfur chemicals are added to the feed in order to be free from poisoning, which usually results in the occurrence of sulfur contamination in the final products. On the other hand, noble-metal catalysts lead exclusively to aromatic ring saturation, resulting in an increased H 2 consumption. , Otherwise, higher reaction temperature is required to produce aromatic compounds . Therefore, the rational design of catalysts, which can break the C–O bond of DBF without the hydrogenation saturation of aromatic rings under mild conditions, is still intrigued and attractive.…”