Influence of iron promoter on catalytic properties of Rh-Mn-Li/SiO2 for CO hydrogenation

Catalytic conversion of syngas into C2+ oxygenates over Rh/SiO2-based catalysts: The remarkable effect of hydroxyls on the SiO2

“…According to the previous results, the high temperature peak centered at 200 • C is ascribed to the reduction of MnO 2 [10,44]. The peaks at 130 • C and 150 • C are ascribed to the reduction of Rh 2 O 3 not intimately contacting with Mn species (denoted as Rh(I)) and of Rh 2 O 3 intimately contacting with Mn species (denoted as Rh(II)), respectively [47,48]. The sample of RML/SiO 2 (CM) also had three peaks which are similar to RML/SiO 2 (SB), but the reduction peak of Rh(II) shifted to a lower temperature and the reduction peak of MnO 2 shifted to a higher temperature compared with that of RML/SiO 2 (SB).…”

An Effective Method of Controlling Metal Particle Size on Impregnated Rh-Mn-Li/SiO2 Catalyst

“…The catalytic hydrogenation of carbon monoxide has attracted much attention in the past decades, mainly due to the growing demand for oxygenated products, particularly C 2 oxygenates such as ethanol, acetaldehyde, acetic acids and/or esters [1][2][3][4]. Many research activities have been carried out in order to acquire the knowledge about the influence of the catalyst nature on the catalytic behavior.…”

Advanced Catalysts Based on Micro‐ and Mesoporous Molecular Sieves for the Conversion of Natural Gas to Fuels and Chemicals

“…Additionally, unpromoted Rh/NaY catalysts can form Rh carbonyl clusters under reaction conditions (250 • C, 100 bar, H 2 /CO = 1), showing high selectivity to acetic acid (up to 40%), again at modest CO conversions below 2% [158]. Thus, despite the academic interest in zeolite-entrapped (promoted) Rh clusters, ideally displaying defined and very homogeneous active sites, allowing to gain fundamental knowledge on the site requirements, their modest catalytic activities compare disfavorably with other Rh-based catalytic systems comprising promoted Rh nanoparticles supported on amorphous SiO 2 [159] or CNTs [160], which show higher time yields to C 2+ oxygenates. To date, no heterogeneous-catalyzed commercial processes for the direct selective synthesis of C 2+ oxygenates from syngas are being operated, and zeolite-supported metal clusters are not considered among the promising catalyst alternatives.…”