Magnesium hydroxide–supported ruthenium as an efficient and stable catalyst for glycerol-selective hydrogenolysis without addition of base and acid additives

Abstract

In this work, the Ru-based catalysts with the synthesized and commercial Mg(OH)2 and MgO as support were prepared at room temperature by a simple chemical reduction approach, such as Ru/Mg(OH)2(S)...

Transition Metal Catalysts for the Glycerol Reduction: Recent Advances

“…Freshly prepared Ru/Mg(OH) 2 catalyst showed the best catalytic activity in the GL hydrogenolysis compared to commercial Ru/Mg(OH) 2 or Ru/ MgO (synthesized or commercial): the synthesized catalyst containing Mg(OH) 2 displayed a cotton-like morphology; Ru was highly dispersed on the support and strong basic active sites were present, leading 1,2-PD with 65 % selectivity and 24 % GL conversion at 483 K and 30 bar H 2 pressure. [213] Poor results were observed in the presence of catalyst containing commercial Mg(OH) 2 : 6 % conversion and 57 % selectivity of 1,2-PD. [213] Mane et al underlined the correlation between the selectivity in GL hydrogenolysis and the precursor used to synthesize the catalyst: Ru/C catalyst prepared from RuCl 3 .…”

“…[213] Poor results were observed in the presence of catalyst containing commercial Mg(OH) 2 : 6 % conversion and 57 % selectivity of 1,2-PD. [213] Mane et al underlined the correlation between the selectivity in GL hydrogenolysis and the precursor used to synthesize the catalyst: Ru/C catalyst prepared from RuCl 3 . 3H 2 O showed high activity in CÀ C cleavage (ethylene glycol selectivity 56 % and 1,2-PD 23 %) while, in the case of Ru(NO)(NO 3 ) 3 precursor, low conversion (< 30 %) but higher selectivity to 1,2-PD (44 %) and lower to ethylene glycol (42 %) were observed at 450-510 K and 52 H 2 bar.…”

New Trends and Perspectives in Production of 1,2-Propanediol

“…However, they cleave the C–C bond of glycerol instead of the C–O bond that decreases selectivity and promotes formation of lower alcohols. Moreover, thermal dehydration of glycerol to acrolein and its cracking to low molecular weight alkanes occur. ,, Moreover, the noble catalysts are costly but offer high ability to dissociate hydrogen molecules. , In contrast, transition metal catalysts are relatively inexpensive and have high resistance to catalytic poisons . Cu-based catalysts are of great interest to researchers because they show better performance in selective C–O bond cleavage of glycerol. , In order to improve the activity and stability of these catalysts, bimetallic systems including Cu–Cr and Cu–Zn are used.…”

“…Moreover, thermal dehydration of glycerol to acrolein and its cracking to low molecular weight alkanes occur. 15,43,47 Moreover, the noble catalysts are costly but offer high ability to dissociate hydrogen molecules. 16,48 In contrast, transition metal catalysts are relatively inexpensive and have high resistance to catalytic poisons.…”

Carbon-supported WOx–Ru-based catalysts for the selective hydrogenolysis of glycerol to 1,2-propanediol

“…Due to the vastness of this topic, the discussion is here limited to the representative cases of Pt and Ru. The comparison of Pt-based bifunctional catalysts prepared by a variety of acid or basic supports demonstrated that one of the most performant systems was achieved by using Pt on Mg/Al basic hydrotalcites: 7,16 at 220 °C and 30 bar of H2, the conversion of glycerol was 92% and the 1,2-PDO selectivity was 93% after 20 h. The dehydrogenation-With respect to Pt-(and even Re-or Rh-) based catalysts, Rubased systems usually display a higher activity for the conversion of glycerol, meaning that the hydrogenolysis may be run under comparatively milder reaction conditions; 18 though, Ru is also efficient in the C-C bond breaking. Studies have clearly highlighted how the reaction is not only affected by the metal/support combination, but also by the metal precursors and the reduction conditions.…”