FULL PAPER Formation of PdNiZn thin film at oil‐water interface: XPS study and application as Suzuki‐Miyaura catalyst Parvin Fatahi | S. Jafar Hoseini Department of Chemistry, Faculty of Sciences, Yasouj University, Yasouj 7591874831, Iran Correspondence S. Jafar Hoseini, Department of Chemistry, Faculty of Sciences, Yasouj University, Yasouj 7591874831, Iran. Email: jhosseini@yu.ac.ir; sjhoseini54@yahoo.com Nanosheet of PdNiZn and nanosphere of PdNiZn/reduced‐graphene oxide (RGO) with sub‐3 nm spheres have been successfully synthesized through a fac- ile oil‐water interfacial strategy. The morphology and composition of the films were determined by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive analysis of X‐ray (EDAX) and elemental mapping. In the present study, we have developed a method to minimize the usage of pre- cious Pd element. Due to the special structure and intermetallic synergies, the PdNiZn and PdNiZn/RGO nanoalloys exhibited enhanced catalytic activity and durability relative to Pd nanoparticles in Suzuki‐Miyaura C‐C cross‐cou- pling reaction. Compared to classical cross‐coupling reactions, this method has the advantages of a green solvent, short reaction times, low catalyst loading, high yields and reusability of the catalysts. KEYWORDS graphene oxide, oil‐water interface, Suzuki‐Miyaura catalyst, thin film, trimetallic alloy nanosheets 1 | INTRODUCTION Trimetallic nanoparticles (NPs) alloy have attracted increasing interest due to their special morphology, size and high surface‐ to‐ volume ratios. [1] Enormous effort has been dedicated to the synthesis of multimetal alloys due to their various advantages. [2] A higher degree of selectivity, higher activity and chemical/physical stability are some of the advantages of trimetallic nanoalloys com- pare to their monometallic or even bimetallic counter- parts. [3,4] Ultrathin noble metal nanocrystals have a potential to exhibit novel properties, especially in the area of catalysis which is related to their high specific surface area. [5] Tremendous efforts have been dedicated to the synthesis of ultrathin nanostructures of noble metals which is limited in comparison with nanostructures of metal hydroxides or sulfides. [6] The importance of trimetallic alloys as a catalyst in one hand and the impor- tance of ultrathin nanostructures on the other hand, encouraged our group to investigate new strategies for the synthesis of ultrathin trimetallic alloy structures like nanosheets or nanospheres. Nanosheets have attracted intensive interest due to their wide range of applica- tions. [7] To obtain these structures, generally specific con- ditions should be applied such as using stabilizers or capping agents to control the growth process. [8] Bao and Tang et al. have synthesized ultrathin Pd nanosheets by using surfactants. [9,10] Till now, there are limited reports on the one‐step synthesis of ultrathin trimetallic nano- sheets or NPs in the absence of stabilizers. Kang et al. have synthesized Au@PdPt NPs with high catalytic activ- ity in the presence of ascorbic acid and hydrazine. [11] Wu et al. have synthesized Au nanostructures on pre‐formed PtNi nanostructures in two steps. [12] Among trimetallic nanocrystals, Pd‐based nanocatalysts have attracted atten- tion because of their physical and chemical performances compare to pure Pd or its bimetallic nanoalloys. [13] Palla- dium components are the best choice catalysts for various Received: 18 August 2017 Revised: 17 October 2017 Accepted: 18 October 2017 DOI: 10.1002/aoc.4187 Appl Organometal Chem. 2017;e4187. https://doi.org/10.1002/aoc.4187 Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/aoc 1 of 11