Subsurface Carbon as a Selectivity Promotor to Enhance Catalytic Performance in Acetylene Semihydrogenation

Abstract

For supported metal catalysts, subsurface sites can significantly influence the adsorption and reaction behaviors on surface sites via the electronic effect and geometric effect. Subsurface carbon in PdC x has been proven to be an effective selectivity promoter in acetylene semihydrogenation. Herein, we theoretically calculated the reaction trajectory on Ni3ZnC0.7 and designed a metal–organic framework-layered hydroxide salt-derived synthesis strategy for the Ni3ZnC0.7/C catalyst. The formation of the flake-like Ni3ZnC0.7 phase was monitored by in situ X-ray diffraction (XRD) and confirmed by XRD, transmission electron microscopy, and selected area electron diffraction characterizations. In acetylene semihydrogenation, the Ni3ZnC0.7/C catalyst had 85% ethylene selectivity even at 100% acetylene conversion, supporting the conclusions from density functional theory calculations. The green oil selectivity was controlled below 2%. All results indicated that incorporating carbon atoms in the subsurface sites significantly enhanced the ethylene selectivity in acetylene semihydrogenation.

Mechanism driven design of trimer Ni1Sb2 site delivering superior hydrogenation selectivity to ethylene

“…In addition, the selectivity to C 4 components of the Ni catalyst is clearly higher than that of the NiSb catalyst. Previous studies showed that the formation of C 4 components in acetylene hydrogenation is mainly attributed to the C-C coupling of strongly adsorbed surface species such as acetylene and vinyl 36 – 39 . The higher selectivity to C 4 components suggests a more facile coupling process on the Ni catalyst.…”

Dual Functionalized Interstitial N Atoms in Co3Mo3N Enabling CO2 Activation

“…into the interstitial site of metals can significantly modify the electronic properties of surface atoms and thus tune the catalytic performance. Transition-metal carbides (carbon atoms are doped into the interstitial sites of the transition metal) are a class of typical catalysts that exhibit enhanced catalytic performance in various catalytic processes due to the unique electronic structure induced by the incorporation of C. − For example, it has been demonstrated that α-MoC, as a special catalyst or functional support, exhibits outperformed performance in catalytic processes related to low-temperature O–H activation, including ultralow temperature water–gas shift reaction, methanol reformation, − and so forth. Moreover, the incorporation of light element atoms into the transition-metal lattice also leads to changes in the geometric properties of surface atoms and thereafter affects the catalytic performance.…”

Understanding the Role of Coordinatively Unsaturated Al3+ Sites on Nanoshaped Al2O3 for Creating Uniform Ni–Cu Alloys for Selective Hydrogenation of Acetylene

“…h i b i t e d .sites but also the escape of ethylene into the gas stream and hence more deactivation is observed 2,10,48. Insight into Effects of the Ni−Cu Structure on Catalytic Behavior.…”