Lithium and boron as interstitial palladium dopants for catalytic partial hydrogenation of acetylene

Abstract

It is demonstrated that light elements, including lithium and boron atoms, can take residence in the octahedral (interstitial) site of a Pd lattice by modifying the electronic properties of the metal nanoparticles, and hence the adsorptive strength of a reactant. The blocking of the sub-surface sites to H in the modified materials results in significantly higher selectivity for the partial catalytic hydrogenation of acetylene to ethylene.

Intercalating lithium into the lattice of silver nanoparticles boosts catalytic hydrogenation of carbon–oxygen bonds

“…Our previous work has detailed a method for the synthesis of a stable interstitial species such as smaller Li, B and C elements into Pd lattice after reduction at elevated temperature, which causes detectable Pd lattice expansion due to electron enrichment to Pd. [53][54][55][56] In contrast, we do not see significant change in Ag lattice for Li + doping, even after reduction at the same temperature, presumably the poor catalytic properties of Ag (see Fig. S7-S8 and Table S2; In order to estimate the degree of lithium ion filling in the interstitials within the Ag lattice, using rapid acquisition X-ray pair distribution function, it is possible to characterize the X-ray scattering atoms/ions patterns due to their unique positions of this lattice.…”

Direct Visualization of Substitutional Li Doping in Supported Pt Nanoparticles and Their Ultra‐selective Catalytic Hydrogenation Performance

“…For example, we reported that interstitial lithium doped palladium (Pd− int Li NPs) can be synthesised by heating the mixture of Li(OAc) ⋅ 2H 2 O and Pd/C at elevated temperatures. The Li (nearly metallic) takes residence in structural distorted interstitial sites under hydrogenation conditions, which can completely suppress the formation of the β‐hydride phase and avoid over‐hydrogenation beyond the target ethylene products [13] …”

“…In this work, we have attempted to synthesise Pt−Li NPs according to a previously reported synthetic strategy with limited Li content [13] . With the aid of SXRD (synchotron X‐ray diffraction) and the associated refinement, we report that the unit cell of the Pt metal lattice contracts after lithiation whilst retaining the parent FCC structure.…”

“…The Li (nearly metallic) takes residence in structural distorted interstitial sites under hydrogenation conditions, which can completely suppress the formation of the β-hydride phase and avoid overhydrogenation beyond the target ethylene products. [13] Binary nanoalloys of Pt with other transition metals are wellresearched; however, alloying Pt with light s-block elements after extensive reduction are hardly explored. To the best of our knowledge, the only example is reported by Ohsaka et al that the electro-deposition of Li on a Pt electrode in propylene carbonate can result in the formation of a PtÀ Li alloy, which exhibited enhanced activity in the catalytic oxidation of formic acid relative to a pristine Pt electrode.…”

Manipulating interstitial carbon atoms in the nickel octahedral site for highly efficient hydrogenation of alkyne

“…More transition metalcatalyzed reactions, however, are controlled by the generation of metastable interstitial atoms [6][7][8][9] . Thus, it is of great interests to explore the control of interstitial site atoms in transition metal catalysts for tuning their catalytic performances [10][11][12] .…”