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A series of 3D self-standing PtRu/Ni(OH)2/NF electrodes is fabricated for electrocatalytic hydrogenation (ECH) of benzoic acid (BA) to cyclohexanecarboxylic acid (CCA). The PtRu/Ni(OH)2electrocatalyst with a unique coral-shaped architecture possesses outstanding charge transfer ability and abundant active sites. The optimized electrode achieves a BA conversion of 99.00% and a CCA selectivity of 100% in 0.05 M H2SO4within 80 min, showing a record faradaic efficiency of 43.90% and high performance during 20 cycles of ECH. In situRaman tests verify the mechanism of the selective hydrogenation of the aromatic ring and density functional theory (DFT) calculations reveal that the electronic interaction between Pt and Ru in the PtRu nanoalloy as well as the electron transfer from the PtRu alloy to the Ni(OH)2nanosheet tunes the electronic states of PtRu/Ni(OH)2, thereby enhancing the adsorption strength of BA on the electrocatalyst surface. This work offers a promising alternative to the traditional catalytic hydrogenation of BA.

Considering the disadvantages of ruthenium-based catalysts for acetylene hydrochlorination, such as poor dispersion, metal loss, serious carbon deposition, and insufficient active sites, supported ruthenium catalysts coated with polydopamine (Ru/AC@PDA-T) were synthesized by using the self-polymerization of dopamine to attach a protective layer on Ru/AC. The PDA-derived layer formed a local active domain depending on the complexation of its heteroatomic structure to the Ru atom. Benefiting from the promotion of local structural forces, the synthetic process resulted in highly dispersed active components, although a certain size of Ru nanoclusters rather than some monatomic species was most favorable for catalyzing the reaction. Ruthenium species were stabilized in their active states. The superior activity might be caused by the synergistic adsorption and activation of reactants by Ru–O/N multi-sites, significantly reducing the catalytic energy barrier, promoting rapid reaction and impeding carbon deposition, which promotes the continuous exposure of active sites and thus improves the catalytic efficiency. Significantly improved activity and stability provide for a potential industrial application of the optimized Ru/AC@PDA-100 catalyst.

With the implementation of the Minamata Convention and the urgent demand for green and efficient mercury-free catalysts, a carbon-supported IPr–(Ru)/AC catalyst was synthesized and assessed for its successful application in acetylene hydrochlorination. The results showed that the interplay between the central Ru and surrounding IPr ensured the stability and high-level dispersion of the active species on the surface of the host; the accelerated electron transfer from the N-heterocycle to Run+boosted the electron cloud density around the active centres, increasing the relative amount of the active constituents. The delocalisation and transfer of electrons in IPr–(Ru) might synergistically improve the ability of the IPr- and Ru-sections in the catalyst to adsorb and activate H–Cl and C2H2, respectively, thus yielding a significant improvement in the original catalytic activity with respect to its counterpart. In addition, the complexation also greatly slowed down the deactivation of the catalyst and endowed the catalyst with a potential industrial application combined with its impressive stability with respect to the original Ru/AC.

Gold and gold-based bimetallic catalysts for acetylene hydrochlorination were prepared with HAuCl4·4H2O and NiCl2·6H2O as precursors, and were analyzed with BET, TG, XRD, TEM, TPR, and XPS. The Au1Ni3/CSs catalyst shows both high activity and good stability, with a C2H2conversion of 95.4% after 46 h under a gas hourly space velocity (GHSV) of C2H2of 900 h−1. The results indicate that the addition of nickel to gold can inhibit the reduction of catalytically active Au3+to Au0and oxidize Au0to Au+during the preparation of Au-based/CSs catalysts, and weaken the occurrence of coke deposition on the catalyst surface, thus improving the stability of the catalyst.