Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

Selective hydrogenation of highly concentrated acetylene streams over mechanochemically synthesized PdAg supported catalysts

“…Overall, the work indicates that similar trends in the catalytic behavior of promoted Pd-based catalysts, particularly PdAg supported catalysts, apply in the selective hydrogenation of acetylene with ethylene present, irrespective of the different reaction conditions operated during our study. 47 Per se , this is an important piece of information, as little is known so far on the crucial features of catalysts, which are most suitable, when the reaction is carried out with high concentrations of acetylene and ethylene at the same time, as in this study.…”

“…44,46 This is done to limit ethylene runaway and consequent formation of a high volume of ethane, when acetylene levels are low and a large excess of ethylene is Catalysis Science & Technology Paper present in gas stream. 47 However, especially in tail-end type reactors, it would actually be beneficial to operate the reaction at higher temperatures to improve the stability of the catalysts, because the low hydrogen partial pressures result in rapid catalyst deactivation. 19 Besides, when acetylene concentration is significantly increased, as in our case, near-complete equilibrium conversion is more easily attained at higher operating temperatures.…”

Functionalized ceria–niobium supported nickel catalysts for gas phase semi-hydrogenation of phenylacetylene to styrene

“…11 The commonly studied supports for selective hydrogenation of alkynes are Al 2 O 3 , SiO 2 and TiO 2 . 12 An emerging support for this reaction is cerium( iv ) oxide (CeO 2 ), which has the potential to switch from Ce 4+ (CeO 2 ) to Ce 3+ (Ce 2 O 3 ) oxidation states under reducible atmosphere. This leads to the formation of non-stoichiometric CeO 2− x oxides (with x values between 0 and 0.5) via the creation of O vacancies on the oxide surface.…”

Highly Active Bimetallic Single-Atom Alloy PdAg Catalysts on Cerium-Containing Supports in the Hydrogenation of Alkynes to Alkenes

“…The selective hydrogenation of alkynes is one of the key and most important reactions in modern catalysis [1][2][3][4]. The large-scale selective hydrogenation of acetylenic hydrocarbons in pyrolysis ethylene or styrene before their polymerization are illustrative examples of the industrial use of this reaction [1,5,6]. The application of the selective hydrogenation of alkynes to fine organic synthesis makes it possible to obtain cis-and trans-olefins as feedstock for the food and pharmaceutical (for example, the synthesis of vitamins A, E, and K) industries and for the production of solvents, detergents, etc.…”

“…Its using as a support Abbreviations and notation: DPA, diphenylacetylene; HRTEM, high resolution transmission electron microscopy; EDX, energy dispersive X-ray spectroscopy; TOF, catalyst turnover frequency; r, the rate of reaction. makes it possible to increase the dispersion of a supported metal and to vary the electron density on metal nanoparticles [5,13,17]. In some cases, sites on the periphery of nanoparticles at the metal-support interface, which include both the nanoparticle metal atoms and the surface atoms of the support, can play an important role.…”