Atomically dispersed catalysts refer to substrate-supported heterogeneous catalysts featuring one or a few active metal atoms that are separated from one another. They represent an important class of materials ranging from single-atom catalysts (SACs) and nanoparticles (NPs). While SACs and NPs have been extensively reported, catalysts featuring a few atoms with well-defined structures are poorly studied. The difficulty in synthesizing such structures has been a critical challenge. Here we report a facile photochemical method that produces catalytic centers consisting of two Ir metal cations, bridged by O and stably bound to a support. Direct evidence unambiguously supporting the dinuclear nature of the catalysts anchored on α-FeO is obtained by aberration-corrected scanning transmission electron microscopy (AC-STEM). Experimental and computational results further reveal that the threefold hollow binding sites on the OH-terminated surface of α-FeO anchor the catalysts to provide outstanding stability against detachment or aggregation. The resulting catalysts exhibit high activities toward HO photooxidation.

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Electrocatalytic conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to value-added 2,5-furandicarboxylic acid (FDCA) is of great significance for sustainable chemical production. The key challenge is to establish an electrocatalytic system with a wide potential window, which can selectively oxidize HMF to FDCA without causing water oxidation. In this study, Cu foam decorated with Cu(OH) 2 (CF-Cu(OH) 2 ) was successfully fabricated as an efficient catalyst, and CuOOH active species generated by electrochemistry were demonstrated as the main catalytic sites for HMF oxidation. As a result, the current density of CF-Cu(OH) 2 reached up to 198.2 mA/cm 2 (100 mM HMF, 1.0 M KOH, 0.8 V vs Ag/AgCl), and a high faradic efficiency close to 100% for FDCA production (yield: 98.7%) was realized. Moreover, we reveal the mechanism for the electro-oxidation of HMF to FDCA and further provide an insight into the oxidation pathway for HMF. A paired electrochemical system exhibits superior catalytic performance of synergetic reactions (HMF oxidation and 4-NP reduction). Therefore, this work proposes a strategy to simultaneously produce two types of value-added chemicals at both electrodes, which can be applied in other electrocatalytic systems for the green synthesis of organic compounds.

Thirteen Cd(II)-containing coordination polymers based on the novel tetradentate ligand tetrakis(imidazol-1-ylmethyl)methane (L), namely, [Cd 2 (L) 13), where H 2 L 1 = fumaric acid, H 2 L 2 = adipic acid, H 2 L 3 = 1,3-benzenedicarboxylic acid, H 2 L 4 = 1,4-benzenedicarboxylic acid, H 2 L 5 = 5-OH-1,3-benzenedicarboxylic acid, H 3 L 6 = 1,3,5-benzenetricarboxylic acid, H 3 L 7 =1,2,3-benzenetricarboxylic acid, H 3 L 8 =1,2,4-benzenetricarboxylic acid, H 4 L 9 =1,2,4,5-benzenetetracarboxylic acid, and H 4 L 10 = 4,4 0 -oxidiphthalic acid, have been synthesized under hydrothermal conditions. Compound L 3 5H 2 O shows a novel three-dimensional (3D) (3,8)-connected supramolecular architecture with a unique (3 3 5 2 ) 2 (3 4 3 4 2 3 5 6 3 6 12 3 7 3 3 8) topology. Compounds 1-3 were isolated by the reactions of L with inorganic anions (SO 4 2-, NO 3 -, Br -). Compound 1 displays a 4-connected PtS network. Compound 2 exhibits a 3D 4-connected zeolite ABW net, while compound 3 is a two-dimensional (2D) (4 4 )-sql net. Compounds 4-8 were isolated by the reactions of L with organic dicarboxylate ligands. 4 exhibits a 2-fold interpenetrating R-Po net, while 5 shows a noninterpenetrating 3D framework. 6 shows a 3D (6 5 3 8) CdSO 4 -type framework, whereas compound 7 has a different 3D framework with (4 3 6 2 3 7 2 3 8)(4 2 3 6 2 3 7 3 8) topology. 8 shows a 2D layer structure, which is further extended into a 3D supramolecular framework by the hydrogen bonds. Compounds 9-11 have been obtained by the reactions of L with organic tricarboxylate ligands. In 9, the Cd(II) atoms are bridged by L and L 6 ligands to form a 3D structure. In 10, the trinuclear Cd(II) clusters are linked by the L and L 7 ligands to generate a chiral 3D R-Po structure. In 11, the Cd(II) centers are connected by the L ligands and the partially deprotonated HL 8 ligand to yield a 2D layer structure. Compounds 12 and 13 were synthesized by the reactions of L with different organic tetracarboxylate ligands. In compound 12, the L 9 ligands link the Cd(II) centers to form a 3D Cd-L 9 framework, and the L ligands further stabilize the 3D structure. In compound 13, L 10 ligands coordinate to the Cd(II) atoms in tetradentate mode to generate a 2D layer, which is further linked by L ligands to form a 3D framework. The structural differences of compounds 1-13 indicate that the presence of the different anions play an important role in the resulting structures of the coordination polymers. The infrared spectra and luminescent properties were also investigated for the compounds.

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This paper presents for the first time a novel method of in situ depositing plasmonic Bi nanoparticles on BiOCl nanosheets (Bi/BiOCl) for PEC water splitting.

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