A general synthesis approach for supported bimetallic nanoparticles via surface inorganometallic chemistry

Abstract

The synthesis of ultrasmall supported bimetallic nanoparticles (between 1 and 3 nanometers in diameter) with well-defined stoichiometry and intimacy between constituent metals remains a substantial challenge. We synthesized 10 different supported bimetallic nanoparticles via surface inorganometallic chemistry by decomposing and reducing surface-adsorbed heterometallic double complex salts, which are readily obtained upon sequential adsorption of target cations and anions on a silica substrate. For example, adsorption of tetraamminepalladium(II) [Pd(NH3)42+] followed by adsorption of tetrachloroplatinate [PtCl42−] was used to form palladium-platinum (Pd-Pt) nanoparticles. These supported bimetallic nanoparticles show enhanced catalytic performance in acetylene selective hydrogenation, which clearly demonstrates a synergistic effect between constituent metals.

Milling Down to Nanometers: A General Process for the Direct Dry Synthesis of Supported Metal Catalysts

“…One example is supported catalysts,which are amultibillion Euro business worldwide, [2] and for which novel synthetic methods are continuously explored. [3][4][5] In the following it is described that aw ide range of different supported catalysts can be produced by simple milling, starting from macroscopic metal powder and as upport material, resulting in nanometer-sized noble metal (and in some cases also base metal) nanoparticles on different supports.T his approach may have very high practical value,s ince milling could become as imple alternative method to the complex solution processing nowadays used in the synthesis of supported catalysts.M oreover, nanoscale dispersion is highly interesting in many other fields,a nd thus these findings have significance also beyond catalysis.…”

Ligand‐Sharing‐Mediated Synthesis of Intermetallic FeM Clusters Embedded in Ultrathin γ‐Fe2O3 Nanosheets

“…Therefore, the nanostructure synthesized from FeCl 3 /PdCl 4 2− was denoted as PdFe/γ‐Fe 2 O 3 NS‐Cl (Figures S6–S10, Supporting Information), while its counterpart nanostructure, which was synthesized from Fe(NO 3 ) 3 /PdCl 4 2− and has similar morphology, was labeled as PdFe/γ‐Fe 2 O 3 NS‐NO 3 (Figures S11–S15, Supporting Information). More intriguingly, in marked contrast to NCs supported on 2D materials,3d,8,16 and PdFe/γ‐Fe 2 O 3 NS‐NO 3 , no particulate can be observed on the surface of the PdFe/γ‐Fe 2 O 3 NS‐Cl in the TEM/SEM/HAADF‐STEM images (Figure a–c). However, a weak, broadened Pd {111} diffraction peak appeared in the X‐ray powder diffraction (XRD) pattern for PdFe/γ‐Fe 2 O 3 NS‐Cl (5.0) (Figure d) 3c.…”

“…This implies that if we can change the structures of the metal precursors from A and B to AB and synthesize bimetallic nanoclusters that are sufficiently small, these highly dynamic bimetallic clusters can be readily converted into thermodynamically stable IMNCs under mild conditions. Herein, we describe a simple but effective strategy to create bimetallic M x Fe y Cl z n − (M = Pd, Au, Ir, Rh, or Ru) precursors, which are formed by sharing a Cl − ligand between FeCl 3 and MCl a b− . According to the Pearson acid–base concept, Fe 3+ is a strong acid and Cl − is a strong base, whereas the Pt group metal anions are weak acids.…”

Microplasmas for Advanced Materials and Devices

“…precursor chemistries and post‐processing (surface functionalization, thermal annealing, etc.) allows synthesis of such particles comprising a large number (e.g., up to seven) of elements and with controlled grain/domain separation, alloying, core–shell structures, etc . A clear opportunity for microplasmas lies in the need to drastically accelerate these processes, with the goal of surpassing existing processes in terms of productivity and precision. Combining microplasmas with microreactor technologies offers an exceptional opportunity to massively parallelize chemical processes in small reactor channels with micrometer dimensions.…”