Platinum is the most effective metal for a wide range of catalysis reactions, but it fails in the formic acid electrooxidation test and suffers from severe carbon monoxide poisoning. Developing highly active and stable catalysts that are capable of oxidizing HCOOH directly into CO2 remains challenging for commercialization of direct liquid fuel cells. A new class of PtSnBi intermetallic nanoplates is synthesized to boost formic acid oxidation, which greatly outperforms binary PtSn and PtBi intermetallic, benefiting from the synergism of chosen three metals. In particular, the best catalyst, atomically ordered Pt45Sn25Bi30 nanoplates, exhibits an ultrahigh mass activity of 4394 mA mg−1 Pt and preserves 78% of the initial activity after 4000 potential cycles, which make it a state‐of‐the‐art catalyst toward formic acid oxidation. Density functional theory calculations reveal that the electronic and geometric effects in PtSnBi intermetallic nanoplates help suppress CO* formation and optimize dehydrogenation steps.

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The D‐π‐A type phosphonium salts in which electron acceptor (A=‐+PR3) and donor (D=‐NPh2) groups are linked by polarizable π‐conjugated spacers show intense fluorescence that is classically ascribed to excited‐state intramolecular charge transfer (ICT). Unexpectedly, salts with π=‐(C6H4)n‐ and ‐(C10H6C6H4)‐ exhibit an unusual dual emission (F1 and F2 bands) in weakly polar or nonpolar solvents. Time‐resolved fluorescence studies show a successive temporal evolution from the F1 to F2 emission, which can be rationalized by an ICT‐driven counterion migration. Upon optically induced ICT, the counterions move from ‐+PR3 to ‐NPh2 and back in the ground state, thus achieving an ion‐transfer cycle. Increasing the solvent polarity makes the solvent stabilization dominant, and virtually stops the ion migration. Providing that either D or A has ionic character (by static ion‐pair stabilization), the ICT‐induced counterion migration should not be uncommon in weakly polar to nonpolar media, thereby providing a facile avenue for mimicking a photoinduced molecular machine‐like motion.

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Polypyrrole/alginate–gelatin conductive hydrogels serve as a repairable circuit and a mechanical sensor.

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Laminar flame speeds of three pentanol isomer (1-, 2-, and 3-pentanol)−air mixtures were measured at equivalence ratios of 0.6−1.8, initial pressures of 0.10−0.75 MPa, and initial temperatures of 393−473 K using the outwardly propagating spherical flame. A recently developed kinetic mechanism of 1-pentanol oxidation (Dagaut model) was used to simulate the laminar flame speeds of 1-pentanol−air mixtures under experimental conditions. A comparison between simulation and measurement shows that the simulation yields good agreement on the stoichiometric and fuel-rich side, but it gives lower values on the fuel-lean side. A kinetic modeling study was performed, and several rate constants of selected elemental reactions were modified on the basis of the sensitivity analysis. The modified model gives good prediction on the laminar flame speed under all experimental conditions. The modified model is also validated against the jet-stirred reactor (JSR) experimental data, and it exhibits good prediction for most species. 1-Pentanol gives the fastest laminar flame speed, followed by 3-and 2-pentanol. 2-and 3-pentanol have very close values considering the experimental uncertainty. With the increase of the pressure, the difference in the laminar flame speed among pentanol isomers is decreased. The flame instability of three pentanol isomers was also analyzed. 2-and 3-pentanol have similar instability behavior with a close density ratio, flame thickness, and Lewis number, while 1-pentanol shows slightly high instability behavior. In comparison to 2-and 3-pentanol, 1-pentanol has a smaller critical radius and Peclect number, and this suggests its high instability behavior.

The growing global concerns to public health from human exposure to perfluorooctanesulfonate (PFOS) require rapid, sensitive, in situ detection where current, state-of-the-art techniques are yet to adequately meet sensitivity standards of the real world. This work presents, for the first time, a synergistic approach for the targeted affinity-based capture of PFOS using a porous sorbent probe that enhances detection sensitivity by embedding it on a microfluidic platform. This novel sorbent-containing platform functions as an electrochemical sensor to directly measure PFOS concentration through a proportional change in electrical current (increase in impedance). The extremely high surface area and pore volume of mesoporous metal–organic framework (MOF) Cr-MIL-101 is used as the probe for targeted PFOS capture based on the affinity of the chromium center toward both the fluorine tail groups as well as the sulfonate functionalities as demonstrated by spectroscopic (NMR and XPS) and microscopic (TEM) studies. Answering the need for an ultrasensitive PFOS detection technique, we are embedding the MOF capture probes inside a microfluidic channel, sandwiched between interdigitated microelectrodes (IDμE). The nanoporous geometry, along with interdigitated microelectrodes, increases the signal-to-noise ratio tremendously. Further, the ability of the capture probes to interact with the PFOS at the molecular level and effectively transduce that response electrochemically has allowed us achieve a significant increase in sensitivity. The PFOS detection limit of 0.5 ng/L is unprecedented for in situ analytical PFOS sensors and comparable to quantification limits achieved using state-of-the-art ex situ techniques.