Properties Of Catalyst Materials Research Articles

Recent Advances on Computational Modeling of Supported Single-Atom and Cluster Catalysts: Characterization, Catalyst–Support Interaction, and Active Site Heterogeneity

To satisfy the need for catalyst materials with high activity, selectivity, and stability for energy conversion, material design and discovery guided by theoretical insights are a necessity. In the past decades, the rise in theoretical investigations into the properties of catalyst materials, reaction mechanisms, and catalyst design principles has shed light on the catalysis field. Quantitative structure–activity relationships have been developed through incorporating spectroscopic simulations, electronic structure calculations, and reaction mechanistic studies. In this review, we report the state-of-the-art computational approaches to catalyst materials characterization for supported single-atom and cluster catalysts utilizing spectroscopic simulations, i.e., XANES simulation, and material properties investigation via electronic-structure calculations. Furthermore, approaches regarding reaction mechanisms, focusing on active site heterogeneity, are also discussed.

Nanochannel-Induced Efficient Water Splitting at the Superhydrophobic Interface.

Constructing a favorable reaction configuration at the water/catalyst interface is crucial for high-efficiency semiconductor-based water splitting. For a long time, a hydrophilic surface of semiconductor catalysts has been considered necessary for efficient mass transfer and adequate contact with water. In this work, by constructing a superhydrophobic PDMS-Ti3+/TiO2 interface (denoted P-TTO) with nanochannels arranged by nonpolar silane chains, we observe overall water splitting efficiencies improved by an order of magnitude under both the white light and simulated AM1.5G solar irradiation compared to the hydrophilic Ti3+/TiO2 interface. The electrochemical overall water splitting potential on the P-TTO electrode also decreased from 1.62 to 1.27 V, which is close to the thermodynamic limit of 1.23 V. Through the in situ diffuse reflection infrared Fourier transform spectroscopy, a nanochannel-induced water configuration transition is directly detected. The density functional theory calculation further verifies the lower reaction energy of water decomposition at the water/PDMS-TiO2 interface. Our work achieves efficient overall water splitting through nanochannel-induced water configurations without changing the bulk of semiconductor catalyst, which reveals the significant role of water status at the interface in the efficiency of the water splitting reaction over the properties of catalyst materials.

Silver nanofibers/ionic liquid nanocomposite based electrochemical sensor for detection of clonazepam via electrochemically amplified detection

In this work, an electrochemical sensing platform based on nanostructured silver fibers (SFs) and Ionic liquid (IL) composite (SFs − IL) was developed for electrochemical sensor. Glassy carbon electrode modified with SFs − IL nanocomposite and used to development of the electrochemical sensor for detection of clonazepam, which increase the reduction peak currents of clonazepam and lowering in the peak potential of clonazepam. The improvement of electrochemical response to clonazepam reduction was found at SFs − IL modified electrode, revealing the synergetic effect of SFs and IL. The properties of catalyst materials were characterized by scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, cyclic voltammetry, differential pulse voltammetry, chronoamperometry and electrochemical impedance spectroscopy. SFs − IL modified electrode offers a wide linear range from 0.1 to 250 μM with a low detection limit of 66 nM, and acceptable reproducibility and stability. Furthermore, the real sample analysis revealed satisfactory recovery for the detection of clonazepam in pharmaceutical formulation, serum and urine samples.