Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub>
One of the key factors for producing highly dispersed controlled nanoparticles is the method used for metal deposition. The decomposition of metal-organic precursors is a good method for deposition of metal nanoparticles with very small sizes and narrow size distributions on the surface of various s...
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doaj-d8b62c4c0b864d7e828f2604eefa023c2021-04-19T23:05:44ZengMDPI AGCrystals2073-43522021-04-011144444410.3390/cryst11040444Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub>Ivan Bondarchuk0Francisco José Cadete Santos Aires1Grigoriy Mamontov2Irina Kurzina3National Research Tomsk State University, 36 Lenin Ave., 634050 Tomsk, RussiaNational Research Tomsk State University, 36 Lenin Ave., 634050 Tomsk, RussiaNational Research Tomsk State University, 36 Lenin Ave., 634050 Tomsk, RussiaNational Research Tomsk State University, 36 Lenin Ave., 634050 Tomsk, RussiaOne of the key factors for producing highly dispersed controlled nanoparticles is the method used for metal deposition. The decomposition of metal-organic precursors is a good method for deposition of metal nanoparticles with very small sizes and narrow size distributions on the surface of various supports. The preparation process of Pd and bimetallic Pd-Sn nanoparticles supported onto γ‑Al<sub>2</sub>O<sub>3</sub> is considered. The samples were prepared by diffusional co-impregnation of the γ‑Al<sub>2</sub>O<sub>3</sub> support by using organometallic Pd(acac)<sub>2</sub> and Sn(acac)<sub>2</sub>Cl<sub>2</sub> precursors. To achieve the formation of Pd and bimetallic Pd-Sn nanoparticles on the support surface, the synthesized samples were then subjected to thermal decomposition under Ar (to decompose the organometallic bound to the surface while keeping the formed nanoparticles small) followed by an oxidation in O<sub>2</sub> (to eliminate the organic compounds remaining on the surface) and a reduction in H<sub>2</sub> (to reduce the nanoparticles oxidized during the previous step). A combination of methods (ICP-OES, TPR-H<sub>2</sub>, XPS, TEM/EDX) was used to compare the physical-chemical properties of the synthesized Pd and bimetallic Pd-Sn nanoparticles supported on the γ‑Al<sub>2</sub>O<sub>3</sub>. The three samples exhibit narrow size distribution with a majority on nanoparticles between 3 and 5 nm. Local EDX measurements clearly showed that the nanoparticles are bimetallic with the expected chemical composition and the measured global composition by ICP-OES. The surface composition and electronic properties of Pd and Sn on the γ-Al<sub>2</sub>O<sub>3</sub> support were investigated by XPS, in particular the chemical state of palladium and tin after each step of thermal decomposition treatments (oxidation, reduction) by the XPS method has been carried out. The reducibility of the prepared bimetallic nanoparticles was measured by hydrogen temperature programmed reduction (TPR-H<sub>2</sub>). The temperature programmed reduction TPR-H<sub>2</sub> experiments have confirmed the existence of strong surface interactions between Pd and Sn, as evidenced by hydrogen spillover of Pd to Sn (Pd-assisted reduction of oxygen precovered Sn). These results lead us to propose a mechanism for the formation of the bimetallic nanoparticles.https://www.mdpi.com/2073-4352/11/4/444bimetallic nanoparticlespalladium-tinpalladium acetylacetonatePd(acac)<sub>2</sub>tin(IV) bis(acetylacetonate) dichlorideSn(acac)<sub>2</sub>Cl<sub>2</sub> |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Ivan Bondarchuk Francisco José Cadete Santos Aires Grigoriy Mamontov Irina Kurzina |
spellingShingle |
Ivan Bondarchuk Francisco José Cadete Santos Aires Grigoriy Mamontov Irina Kurzina Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub> Crystals bimetallic nanoparticles palladium-tin palladium acetylacetonate Pd(acac)<sub>2</sub> tin(IV) bis(acetylacetonate) dichloride Sn(acac)<sub>2</sub>Cl<sub>2</sub> |
author_facet |
Ivan Bondarchuk Francisco José Cadete Santos Aires Grigoriy Mamontov Irina Kurzina |
author_sort |
Ivan Bondarchuk |
title |
Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub> |
title_short |
Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub> |
title_full |
Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub> |
title_fullStr |
Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub> |
title_full_unstemmed |
Preparation and Investigation of Pd and Bimetallic Pd-Sn Nanocrystals on γ-Al<sub>2</sub>O<sub>3</sub> |
title_sort |
preparation and investigation of pd and bimetallic pd-sn nanocrystals on γ-al<sub>2</sub>o<sub>3</sub> |
publisher |
MDPI AG |
series |
Crystals |
issn |
2073-4352 |
publishDate |
2021-04-01 |
description |
One of the key factors for producing highly dispersed controlled nanoparticles is the method used for metal deposition. The decomposition of metal-organic precursors is a good method for deposition of metal nanoparticles with very small sizes and narrow size distributions on the surface of various supports. The preparation process of Pd and bimetallic Pd-Sn nanoparticles supported onto γ‑Al<sub>2</sub>O<sub>3</sub> is considered. The samples were prepared by diffusional co-impregnation of the γ‑Al<sub>2</sub>O<sub>3</sub> support by using organometallic Pd(acac)<sub>2</sub> and Sn(acac)<sub>2</sub>Cl<sub>2</sub> precursors. To achieve the formation of Pd and bimetallic Pd-Sn nanoparticles on the support surface, the synthesized samples were then subjected to thermal decomposition under Ar (to decompose the organometallic bound to the surface while keeping the formed nanoparticles small) followed by an oxidation in O<sub>2</sub> (to eliminate the organic compounds remaining on the surface) and a reduction in H<sub>2</sub> (to reduce the nanoparticles oxidized during the previous step). A combination of methods (ICP-OES, TPR-H<sub>2</sub>, XPS, TEM/EDX) was used to compare the physical-chemical properties of the synthesized Pd and bimetallic Pd-Sn nanoparticles supported on the γ‑Al<sub>2</sub>O<sub>3</sub>. The three samples exhibit narrow size distribution with a majority on nanoparticles between 3 and 5 nm. Local EDX measurements clearly showed that the nanoparticles are bimetallic with the expected chemical composition and the measured global composition by ICP-OES. The surface composition and electronic properties of Pd and Sn on the γ-Al<sub>2</sub>O<sub>3</sub> support were investigated by XPS, in particular the chemical state of palladium and tin after each step of thermal decomposition treatments (oxidation, reduction) by the XPS method has been carried out. The reducibility of the prepared bimetallic nanoparticles was measured by hydrogen temperature programmed reduction (TPR-H<sub>2</sub>). The temperature programmed reduction TPR-H<sub>2</sub> experiments have confirmed the existence of strong surface interactions between Pd and Sn, as evidenced by hydrogen spillover of Pd to Sn (Pd-assisted reduction of oxygen precovered Sn). These results lead us to propose a mechanism for the formation of the bimetallic nanoparticles. |
topic |
bimetallic nanoparticles palladium-tin palladium acetylacetonate Pd(acac)<sub>2</sub> tin(IV) bis(acetylacetonate) dichloride Sn(acac)<sub>2</sub>Cl<sub>2</sub> |
url |
https://www.mdpi.com/2073-4352/11/4/444 |
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