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Preparation of single atom catalysts (SACs) is of broad interest to materials scientists and chemists but remains a formidable challenge. Herein, we develop an efficient approach to synthesize SACs via a precursor-dilution strategy, in which metalloporphyrin (MTPP) with target metals are co-polymerized with diluents (tetraphenylporphyrin, TPP), followed by pyrolysis to N-doped porous carbon supported SACs (M 1 /N-C). Twenty-four different SACs, including noble metals and non-noble metals, are successfully prepared. In addition, the synthesis of a series of catalysts with different surface atom densities, bi-metallic sites, and metal aggregation states are achieved. This approach shows remarkable adjustability and generality, providing sufficient freedom to design catalysts at atomic-scale and explore the unique catalytic properties of SACs. As an example, we show that the prepared Pt 1 /N-C exhibits superior chemoselectivity and regioselectivity in hydrogenation. It only converts terminal alkynes to alkenes while keeping other reducible functional groups such as alkenyl, nitro group, and even internal alkyne intact.

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The design of cheap, non-toxic, and earth-abundant transition metal catalysts for selective hydrogenation of alkynes remains a challenge in both industry and academia. Here, we report a new atomically dispersed copper (Cu) catalyst supported on a defective nanodiamond-graphene (ND@G), which exhibits excellent catalytic performance for the selective conversion of acetylene to ethylene, i.e., with high conversion (95%), high selectivity (98%), and good stability (for more than 60 h). The unique structural feature of the Cu atoms anchored over graphene through Cu-C bonds ensures the effective activation of acetylene and easy desorption of ethylene, which is the key for the outstanding activity and selectivity of the catalyst.

The mechanism on interfacial synergistic catalysis for supported metal catalysts has long been explored and investigated in several important heterogeneous catalytic processes (e.g., water-gas shift (WGS) reaction). The modulation of metal-support interactions imposes a substantial influence on activity and selectivity of catalytic reaction, as a result of the geometric/electronic structure of interfacial sites. Although great efforts have validated the key role of interfacial sites in WGS over metal catalysts supported on reducible oxides, direct evidence at the atomic level is lacking and the mechanism of interfacial synergistic catalysis is still ambiguous. Herein, Ni nanoparticles supported on TiO (denoted as Ni@TiO) were fabricated via a structure topotactic transformation of NiTi-layered double hydroxide (NiTi-LDHs) precursor, which showed excellent catalytic performance for WGS reaction. In situ microscopy was carried out to reveal the partially encapsulated structure of Ni@TiO catalyst. A combination study including in situ and operando EXAFS, in situ DRIFTS spectra combined with TPSR measurements substantiates a new redox mechanism based on interfacial synergistic catalysis. Notably, interfacial Ni species (electron-enriched Ni site) participates in the dissociation of HO molecule to generate H, accompanied by the oxidation of Ni-O -Ti (O : oxygen vacancy) to Ni-O-Ti structure. Density functional theory calculations further verify that the interfacial sites of Ni@TiO catalyst serve as the optimal active site with the lowest activation energy barrier (∼0.35 eV) for water dissociation. This work provides a fundamental understanding on interfacial synergistic catalysis toward WGS reaction, which is constructive for the rational design and fabrication of high activity heterogeneous catalysts.

Direct synthesis of aromatics from syngas is a great challenge because of severe operating conditions and low yield of aromatics. Making this process more competitive than the MTA (methanol to aromatics) process will require high energy efficiency and low CO 2 emission. A combination of Na-Zn-Fe 5 C 2 and hierarchical HZSM-5 with uniform mesopores dramatically changed the product distribution of Fischer-Tropsch synthesis, leading to 51% aromatic selectivity under the stable stage with CO conversion >85%. C 12+ heavy hydrocarbons almost disappeared, and the catalyst showed good stability. The hierarchical zeolitic structure and Brønsted acidity of HZSM-5 could be precisely tuned by controlling the alkali treatment conditions and the degree of ion exchange. The appropriate density and strength of the Brønsted acid sites and the hierarchical pore structure of HZSM-5 endowed the catalyst with an unprecedented aromatic yield. This work shows a broad area for development for syngas conversion.Recently, a high-performance catalyst, Na-Zn-Fe 5 C 2 (termed as FeZnNa), was developed by the co-precipitation method (Figures S1-S3). 22 The molar weight ratio of

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Methanol−water reforming is a promising solution for H 2 production/transportation in stationary and mobile hydrogen applications. Developing inexpensive catalysts with sufficiently high activity, selectivity, and stability remains challenging. In this paper, nickel-supported over face-centered cubic (fcc) phase α-MoC has been discovered to exhibit extraordinary hydrogen production activity in the aqueous-phase methanol reforming reaction. Under optimized condition, the hydrogen production rate of 2% Ni/α-MoC is about 6 times higher than that of conventional noble metal 2% Pt/Al 2 O 3 catalyst. We demonstrate that Ni is atomically dispersed over α-MoC via carbon bridge bonds, forming a Ni 1 −C x motif on the carbide surface. Such Ni 1 −C x motifs can effectively stabilize the isolated Ni 1 sites over the α-MoC substrate, rendering maximized active site density and high structural stability. In addition, the synergy between Ni 1 −C x motif and α-MoC produces an active interfacial structure for water dissociation, methanol activation, and successive reforming processes with compatible activity.