How to maximize the number of desirable active sites on the surface of the catalyst and minimize the number of sites promoting undesirable side reactions is currently an important research topic. In this study, a new way based on the synergism to achieve the successful fabrication of an ordered heterobimetallic self-assembled monolayer (denoted as BMSAM ) with a controlled composition and an excellent orientation of metals in the monolayer was developed. BMSAM consisting of phenanthroline and Schiff-base groups was prepared, and its novel heterobimetallic (Cu and Pd) self-assembled monolayer anchored in silicon (denoted as Si-Fmp-Cu-Pd BMSAM ) with a controlled composition and a fixed position was fabricated and characterized by UV, cyclic voltammetry, Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and water-drop contact angle (WDCA) analyses. The effects of Si-Fmp-Cu-Pd BMSAM on its catalytic properties were also systematically investigated using “click” reaction as a template by WDCA, XPS, SEM, XRD, ICP-AES and in situ Fourier transform infrared analyses in a heterogeneous system. The results showed that the excellent catalytic characteristic could be attributed to the partial (ordered or proper distance) isolation of active sites displaying high densities of specific atomic ensembles. The catalytic reaction mechanism of the click reaction interpreted that the catalytic process mainly occurred on the surface of the monolayer, internal active site (Pd) and rationalized that the Cu(I) species and Pd(0) reduced from the Cu(II) and Pd(II) catalyst were active species, which had a proper distance between two different metals. The cuprate–triazole intermediate and the palladium intermediate, whose production is the key step, should lie in a proper position between the copper and active palladium sites, with which the reaction rate of transmetalation would be improved to increase the amount of the undesired Sonogashira coupling product.

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The synergistic effect between Ni and Pd atom was the crucial factor for enhancing catalytic activity.

Fabrication, arrangement, and controllable composition of ordered organometallic films are critical for designing a highly active catalyst and investigating the catalytic mechanism. In this paper, an organometallic terpyridine Pd(II)/Ni(II) monolayer linked on the silicon substrate surface (denoted as <strong>Si-Tpy-Pd₁/Ni₁</strong>) was prepared and characterized using water contact angle, ultraviolet spectra, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron microscopy. <strong>Si-Tpy-Pd₁/Ni₁</strong> exhibited high catalytic activity, substrate applicability, and reusability after 5 runs. During recycling, the deactivation was induced by the aggregation of active Pd/Ni nanoparticles. The catalytic mechanism was heterogeneous and occurred on the <strong>Si-Tpy-Pd₁/Ni₁</strong> monolayer surface; the mechanism was confirmed using hot filtrate, poison test, and a three-phase experiment. The real active center was Pd^δ^–/Ni^δ+ and was formed in situ on the organometallic monolayer surface, which acted as a precursor with a synergistic effect between Pd and Ni. The electron density of Pd became more negative because of electron transfer from Ni to Pd, which facilitated the oxidative addition reaction.