Synthesis of Quasi‐Bilayer Subnano Metal‐Oxide Interfacial Cluster Catalysts for Advanced Catalysis

Abstract

Planar metal clusters possess high metal utilization, distinct electronic properties, and catalytic functions from their 3D counterparts. However, synthesis of these materials is challenging due to much elevated surface free energies. Here it is reported that silica supported planar bilayer Pt‐CoOx subnano clusters, consisting of approximately one atomic layer of Pt and one CoOx layer on top, can be achieved by employing strong‐electrostatic interactions during impregnation and precisely‐controlled CoOx coating using atomic layer deposition. Such bilayer structure is unambiguously confirmed by electron microscopy and in situ X‐ray absorption fine spectroscopy which is never reported before. This synthetic approach can be extended to another eight permutations of planar metal‐oxide subnano clusters. The resulting bilayer catalysts, owing to unique electronic properties and the abundant metal‐oxide interfaces created, exhibit excellent catalytic performances in the reactions of preferential oxidation of CO in H2 and selective hydrogenation of acetylene, by showing much higher selectivity and intrinsic activities at least 8 and 48 times greater than those conventional oxide coated 3D metal clusters/nanoparticles, highlighting the advances of bilayer interfacial structure. These findings open a new avenue to design abundant and highly active metal‐oxide interfaces for advanced metal catalysis.

Dehydrogenation of Ammonia Borane by Platinum‐Nickel Dimers: Regulation of Heteroatom Interspace Boosts Bifunctional Synergetic Catalysis

“…[13] Next, NiO x ALD was performed on Pt 1 /C 3 N 4 for another cycle by alternatively exposing nickelocene (NiCp 2 ) and O 3 at 200 °C to achieve the dimeric Pt 1 Ni 1 /C 3 N 4 catalyst (Scheme 1). [14] In this case, Ni atoms nucleate on the predeposited Pt atoms as well as the open C 3 N 4 support by forming Pt 1 Ni 1 dimers along with isolated Ni 1 atoms. To obtain the Pt 1 + Ni 1 HDSAC (denoted as Pt 1 + Ni 1 /C 3 N 4 ), ALD was executed by sequentially exposing the C 3 N 4 support to MeCpPtMe 3 , NiCp 2 , and O 3 at 200 °C; therein, steric hindrance between chemisorbed MeCpPtMe 3 and NiCp 2 precursors ensures the inhibition of direct nucleation of NiCp 2 on Pt, and O 3 was used to simultaneously remove the ligands of chemisorbed MeCpPtMe 3 and NiCp 2 precursors to form the Pt 1 + Ni 1 HDSAC.…”

Atomic Lego Catalysts Synthesized by Atomic Layer Deposition

“…Kinetic studies revealed that the mass-specific rate at room temperature was 5.21 mol CO h –1 g Pt –1 over 1cFe-Pt/SiO 2 , which is about 30 times greater than that for Pt/Fe 2 O 3 (Figure c). Similar results were also found on FeO x -coated Ir/SiO 2 and CoO x -coated Pt/SiO 2 samples in the PROX reaction. , In this work, in situ XAFS measurements showed that atomically dispersed Fe 1 (OH) x species on Pt NPs exhibited a strikingly high reducibility, a fact that can be reduced from Fe 3+ to Fe 2+ at room temperature by H 2 , which is sharply distinct from the reduction of Fe n (OH) x clusters above 200 °C. Such a strikingly high reducibility might play an important role in the high performance of 1cFe-Pt/SiO 2 .…”