Palladium clusters have been synthesized by the "ship-in-a-bottle" approach in the supercages of NaX and NaY faujasite zeolites. In comparison with CO adsorbed on a bulk Pd electrode, the same molecule adsorbed on the Pd clusters electrodes evoked an enhanced IR absorption (EIRA). The enhancement factors have been determined to be about 38 and 51 in NaX and NaY, respectively. IR band centers of linear-bonded CO, bridge-bonded CO, and multi-bonded CO in NaX are measured, respectively, 12, 14, and 11 cm(-1) lower than those of the corresponding adsorption modes in NaY. The adsorption of CO and the oxidation of adsorbed CO in NaX matrix are faster than that in NaY matrix. These results suggest that part of the Pd2+ ions in NaX are located in sites III and III' that are near the 12-ring window of the supercage of zeolite, which lead to the formation of small Pd clusters. The present study is of significant importance in exploring the dependence of catalyst properties on structures, as well as in understanding and predicting the locations and properties of metal clusters in zeolites.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp0480089 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A novel cerium-based metal-organic framework supported Pd catalyst for semi-hydrogenation of phenylacetylene.
Inorg Chem Front
December 2024
Department of Chemistry, University of Manchester Manchester M13 9PL UK
Phenylacetylene is a detrimental impurity in the polymerisation of styrene, capable of poisoning catalysts even at ppm levels and significantly degrading the quality of polystyrene. The semi-hydrogenation of phenylacetylene to styrene instead of ethylbenzene is, therefore, an important industrial process. We report a novel cerium(iv)-based metal-organic framework (denoted as Ce-bptc), which comprises {Ce} clusters bridged by biphenyl-3,3',5,5'-tetracarboxylate linkers.
View Article and Find Full Text PDFSite-selective decarbonylative [4 + 2] annulation of carboxylic acids with terminal alkynes by C-C/C-H activation strategy and cluster catalysis.
Chem Sci
December 2024
School of Chemistry and Chemical Engineering, Hainan University Haikou 570228 China
Article Synopsis
- The manuscript presents a novel palladium-catalyzed cyclization method using carboxylic acids and terminal alkynes, which showcases its potential for creating complex organic molecules.
- This technique is significant as it allows carboxylic acids, traditionally underutilized, to serve as effective building blocks in intramolecular cycloaddition and addresses long-standing challenges in synthesizing substituted naphthalenes.
- The reaction demonstrates a wide range of substrate compatibility and functional group tolerance, making it applicable for scalable synthesis in organic chemistry, drug discovery, and material science.
Improving the Chemical Utilization Efficiency of Pd Hydrodechlorination Catalysts through Hydrogen-Spillover Empowered Synergy between Pd and TiNiN Support.
Environ Sci Technol
December 2024
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
The sustainable and affordable environmental application of Pd catalysis needs further improvement of Pd mass activity. Besides the well-recognized importance of physical utilization efficiency─the ratio of surface atoms forming reactant-accessible reactive sites─a lesser-known fact is that the congestion of these reactive sites, which we term as the chemical utilization efficiency, also influences the mass activity. Herein, by leveraging the 100% physical utilization efficiency of a fully exposed Pd cluster (Pd) and the hydrogenation activity of TiNiN, we developed Pd/TiNiN as a high physical and chemical utilization efficiency catalyst.
View Article and Find Full Text PDFMorphological analysis of Pd/C nanoparticles using SEM imaging and advanced deep learning.
RSC Adv
October 2024
School of Electrical and Electronic Engineering, Hanoi University of Science and Technology Hanoi Vietnam
In this study, we present a comprehensive approach for the morphological analysis of palladium on carbon (Pd/C) nanoparticles utilizing scanning electron microscopy (SEM) imaging and advanced deep learning techniques. A deep learning detection model based on an attention mechanism was implemented to accurately identify and delineate small nanoparticles within unlabeled SEM images. Following detection, a graph-based network was employed to analyze the structural characteristics of the nanoparticles, while density-based spatial clustering of applications with noise was utilized to cluster the detected nanoparticles, identifying meaningful patterns and distributions.
View Article and Find Full Text PDFControlled Synthesis and Phase Transition Mechanisms of Palladium Selenide: A First-Principles Study.
Precis Chem
October 2024
School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong China.
Using density functional theory, we carefully calculated the relative stability of monolayer, few-layer, and cluster structures with Penta PdSe, T-phase PdSe, and PdSe-phase. We found that the stability of Penta PdSe increases with the number of layers. The Penta PdSe, T-phase PdSe, and PdSe monolayers are all semiconducting, with band gaps of 1.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!