Structure of Hydrothermally Stable Acid Sites and their Catalytic Role in P-Modified ZSM-5 Zeolite Revealed by Solid-State NMR Spectroscopy.

The ZSM-5 zeolite is the key active component in high-severity fluid catalytic cracking (FCC) catalysts and is routinely activated by phosphorus compounds in industrial production. To date, however, the detailed structure and function of the introduced phosphorus still remain ambiguous, which hampers the rational design of highly efficient catalysts. In this work, using advanced solid-state NMR techniques, we have quantitatively identified a total of seven types of P-containing complexes in P-modified ZSM-5 zeolite and clearly revealed their structure, location, and catalytic role.

Additives-Modified Electrodeposition for Synthesis of Hydrophobic Cu/CuO with Ag Single Atoms to Drive CO Electroreduction.

Copper-based electrocatalysts are recognized as crucial catalysts for CO electroreduction into multi-carbon products. However, achieving copper-based electrocatalysts with adjustable valences via one-step facile synthesis remains a challenge. In this study, Cu/CuO heterostructure is constructed by adjusting the anion species of the Cu ions-containing electrolyte during electrodeposition synthesis.

Charge-transfer complexation of coordination cages for enhanced photochromism and photocatalysis.

Intensified host-guest electronic interplay within stable metal-organic cages (MOCs) presents great opportunities for applications in stimuli response and photocatalysis. Zr-MOCs represent a type of robust discrete hosts for such a design, but their host-guest chemistry in solution is hampered by the limited solubility. Here, by using pyridinium-derived cationic ligands with tetrakis(3,5-bis(trifluoromethyl)phenyl)borate (BAr) as solubilizing counteranions, we report the preparation of soluble Zr-MOCs of different shapes (1-4) that are otherwise inaccessible through a conventional method.

Product oriented upcycling of waste polyethylene terephthalate plastic and carbon dioxide via decoupled electrolysis.

End-of-life plastics and carbon dioxide (CO2) are anthropogenic waste carbon resources; it is imperative to develop efficient technologies to convert them to value-added products. Here we report the upcycling of polyethylene terephthalate (PET) plastic and CO2 toward valuable potassium diformate, terephthalic acid, and H2 fuel via decoupled electrolysis. This product-oriented process is realized by two electrolyzers: (1) a solid-state-electrolyte based CO2 electrolyzer and (2) a solid-polymer-electrolyte-based PET electrolyzer.

High-Entropy Alloy Nanoflower Array Electrodes with Optimizable Reaction Pathways for Low-Voltage Hydrogen Production at Industrial-Grade Current Density.

Developing sufficiently effective non-precious metal catalysts for large-current-density hydrogen production is highly significant but challenging, especially in low-voltage hydrogen production systems. Here, we innovatively report high-entropy alloy nanoflower array (HEANFA) electrodes with optimizable reaction pathways for hydrazine oxidation-assisted hydrogen production at industrial-grade current densities. Atomic-resolution structural analyses confirm the single-phase solid-solution structure of HEANFA.

Study on the Effect of Structure and Acidity of Hydrocracking Catalyst Support on the Selectivity of Middle Distillate.

Hydrocracking has become the main technology for producing diesel fuel in many refineries, the key process to meeting new product specifications as environmental regulations for transportation fuels become more stringent. The efficacy of the hydrocracking catalyst is a pivotal determinant of the reaction performance. This study leveraged high-throughput experimentation to closely examine the impact of support properties on both the catalytic activity and the selectivity of middle distillates.

CO-Tolerant Heterogeneous Ruthenium Catalysts for Efficient Formic Acid Dehydrogenation.

The development of improved and less costly catalysts for dehydrogenation of formic acid (HCOOH) is of general interest for renewable energy technologies involving hydrogen storage and release. Theoretical calculations reveal that ruthenium (Ru) nanoparticles supported on nitrogen-doped carbon should be appropriate catalysts for such transformations. It is predicted that nitrogen doping significantly decreases the formation of CO, but at the same time increases CO tolerance of the catalysts.

Hydrogenation Reaction Mechanisms on Ni-Doped MoS Catalysts: A Density Functional Theory Study of Sulfur Edge Engineering and Coregulated Electronic Effects.

Precise modulation of local interatomic interactions affecting the electronic structure is an important method to control the catalytic activity and reaction pathways. In this study, we focused on the hydrogenation reaction of naphthalene and employed density functional theory calculations to investigate the specific influence of electronic effects triggered by the coregulation of Ni and sulfur edge engineering on the hydrogenation performance of Ni-doped MoS at different edge sulfur coverages (Ni-MoS-X-θ). Our findings reveal that the interaction between Ni and S in the catalyst matrix material modifies the local electronic structure surrounding the sulfur atoms in the active site.

New near-infrared fluorescent probe for imaging superoxide anion of cell membrane.

Selective imaging of superoxide anion is important for understanding its role in cell membrane biology, but is often a challenging task because of the lack of an effective fluorescence probe. In this study, a new near-infrared fluorescent probe (SHX-O) that can target cell membrane was developed for imaging superoxide anion. SHX-O was designed by simultaneously incorporating a sulfonated bis-indole and a diphenylphosphinyl recognition group into the hemicyanine moiety.

Gas-delivery membrane as an alternative aeration method to remove dissolved methane from anaerobically treated wastewater.

Dissolved methane is a hurdle for anaerobic wastewater treatment, which would be stripped into the atmosphere by conventional bubble aeration and increase the release of greenhouse gases into the environment. The high oxygen transfer efficiency and less turbulence in membrane aerated biofilm reactor (MABR) could prevent the stripping of dissolved methane. In this study, an MABR was established to remove dissolved methane aerobically in parallel to the nitrogen removal driven by the anammox process.

New insights on zero-valent iron permeable reactive barrier for Cr(VI) removal: The function of FeS reaction zone downstream in-situ generated by sulfate-reducing bacteria.

The biogeochemical behavior downstream of the zero-valent iron permeable reactive barrier (ZVI-PRB) plays an enormous positive role in the remediation of contaminated-groundwater, but has been completely neglected for a long time. Therefore, this study conducted a 240-day SRB-enhanced ZVI-PRB column experiment, focusing on what exactly happens downstream of ZVI-PRB. Results show that biosulfidation of SRB inside ZVI-PRB prolonged the complete Cr(VI) removal longevity of ZVI-PRB from 38 days to at least 240 days.

Transformation of iron-minerals from natural aquifer media by sulfate-reducing bacteria: Behavior, mechanism, and Cr(VI) removal.

Sulfate-reducing bacteria (SRB) and iron minerals are widespread in subsurface environments, where their mediated Fe and S transformations are crucial for contaminant immobilization. However, the mechanism mediated by SRB to transform natural iron minerals into reduced iron-sulfur compounds and the contaminant removal capacity of the transformation products remain unclear. Herein, the mechanism of native SRB-mediated transformation of iron-minerals from natural aquifer media into biogenic ferrous sulfide (FeS) was revealed and the Cr(VI) removal performance of the transformation product was evaluated.

A Rapid Analysis Method for Determination of Hydrocarbon Types in Aviation Turbine Fuel by Gas Chromatography-Mass Spectrometry.

A rapid analysis method for determination of hydrocarbon types in aviation turbine fuel was investigated in this study. A kind of reversible adsorption material packed as an unsaturated trap was used to separate saturated hydrocarbons and unsaturated hydrocarbons in the GC-MS system. No manual process or organic reagent was needed during the entire analysis process.

Overcoming the Limitation of Ionomers on Mass Transport and Pt Activity to Achieve High-Performing Membrane Electrode Assembly.

The membrane electrode assembly (MEA) is one of the critical components in proton exchange membrane fuel cells (PEMFCs). However, the conventional MEA cathode with a covered-type catalyst/ionomer interfacial structure severely limits oxygen transport efficiency and Pt activity, hardly achieving the theoretical performance upper bound of PEMFCs. Here, we design a noncovered catalyst/ionomer interfacial structure with low proton transport resistance and high oxygen transport efficiency in the cathode catalyst layer (CL).

Interface engineering of Platinum-Copper alloy/titanium dioxide for enhanced photocatalytic carbon dioxide reduction.

To develop an efficient photocatalytic carbon dioxide (CO) reduction aimed at mitigating CO emissions and greenhouse effects, we propose a straightforward strategy involving hydrogen reduction treatment of PtCu/Ti to create the PtCu/Ti-H catalyst with a distinctive interface structure. Compared with the fresh PtCu/Ti catalyst and the benchmark anatase TiO, the CH production of the PtCu/Ti-H catalyst increased by 2 times and 81.6 times, respectively.

pH dependence of reactive oxygen species generation and pollutant degradation in Fe(II)/O/tripolyphosphate system.

It has been reported that tripolyphosphate (TPP) can effectively enhance the activation of O by Fe(II) to remove organic pollutants in the environment. However, the influence of solution pH on the generation and conversion of reactive oxygen species (ROS) and their degradation of pollutants in the Fe(II)/O/TPP system needs further investigation. In this study, we demonstrated that O and •OH were the main ROS responsible for degradation in the system at different pH conditions, and their formation rates were calculated using a steady-state model.

A Stand-Off Laser-Induced Breakdown Spectroscopy (LIBS) System for Remote Bacteria Identification.

Bacteria are the primary cause of infectious diseases, making rapid and accurate identification crucial for timely pathogen diagnosis and disease control. However, traditional identification techniques such as polymerase chain reaction and loop-mediated isothermal amplification are complex, time-consuming, and pose infection risks. This study explores remote (~3 m) bacterial identification using laser-induced breakdown spectroscopy (LIBS) with a Cassegrain reflective telescope.

Generation of Triplet States by Host-Stabilized Through-Space Conjugation for the Construction of Efficient Supramolecular Photocatalysts.

Promoting the generation of triplet states is essential for developing efficient photocatalytic systems. This research presents a novel approach of host-stabilized through-space conjugation via the combination of covalent and non-covalent methods. The designed building block, 4,4'-(1,4(1,4)-dibenzene cyclohexaphane-1,4-diyl)bis(1-phenylpyridinium) chloride, features inherently stable through-space conjugation.

First-Principles Calculations of the Effect of γ-Alumina Surface Hydroxyl Structures on the Location and Dechlorination of a Platinum Precursor.

The interaction between Pt precursors and alumina support is an important step in synthesizing Pt/AlO catalysts, while an in-depth understanding of the interaction is still lacking. Herein, density functional theory (DFT) calculations were performed to simulate the coordination of HPtCl with different surface hydroxyl groups, revealing the influence of the γ-AlO surface hydroxyl structure on the position of the Pt precursor and the removal of Cl ligands. After drying, the interaction mechanism between [PtCl] and alumina support involves hydrogen bonds and van der Waals forces, which are the main driving forces for the structural transformation from [PtCl] coordinated with the surface hydroxyl group into the PtCl(OH) species (OH is the γ-AlO surface group).

Lighting Up Bispyrene-Functionalized Chiral Molecular Muscles with Switchable Circularly Polarized Excimer Emissions.

Aiming at the further extension of the application scope of traditional molecular muscles, a novel bispyrene-functionalized chiral molecular [c2]daisy chain was designed and synthesized. Taking advantage of the unique dimeric interlocked structure of molecular [c2]daisy chain, the resultant chiral molecular muscle emits strong circularly polarized luminescence (CPL) attributed to the pyrene excimer with a high dissymmetry factor (g) value of 0.010.