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The use of methane as one of the cleanest energy sources has attracted significant public awareness, and methane production processes with less environmental impact than fracking are receiving considerable attention. Catalytic hydrocracking of plastic materials has been considered a potential clean alternative. However, catalysts that convert heterogeneous plastic feeds into a single product under industrially relevant conditions are lacking. Here, we describe a Ru-modified zeolite that catalytically transforms polyethylene, polypropylene, and polystyrene into grid-compatible methane (>97% purity), at 300 degrees C-350 degrees C using near-stoichiometric amounts of H-2. Mechanistic studies reveal a chain-end initiation process with limited isomerization of plastic substrates. A Ru site-dominant mechanism is proposed based on these studies and density functional theory (DFT) computations. We foresee that such a plastic-to-methane process may increase the intelligent use of plastic waste via energy recovery. There is also the potential to accommodate emerging sustainable H-2 production into existing natural gas networks, while integrating waste management, fuel production, and energy storage.

Summary Short-term synaptic plasticity, the dynamic alteration of synaptic strength during high-frequency activity, is a fundamental characteristic of all synapses. At the calyx of Held, repetitive activity eventually results in short-term synaptic depression, which is in part due to the gradual exhaustion of releasable synaptic vesicles. This is counterbalanced by Ca 2+ -dependent vesicle replenishment, but the molecular mechanisms of this replenishment are largely unknown. We studied calyces of Held in knockin mice that express a Ca 2+ -Calmodulin insensitive Munc13-1 W464R variant of the synaptic vesicle priming protein Munc13-1. Calyces of these mice exhibit a slower rate of synaptic vesicle replenishment, aberrant short-term depression and reduced recovery from synaptic depression after high-frequency stimulation. Our data establish Munc13-1 as a major presynaptic target of Ca 2+ -Calmodulin signaling and show that the Ca 2+ -Calmodulin-Munc13-1 complex is a pivotal component of the molecular machinery that determines short-term synaptic plasticity characteristics.

The chromium–carbon–sulfur (Cr–C–S) deposits were electroplated from a trivalent Cr bath containing thiosalicylic acid. In the absence of thiosalicylic acid, the Cr–C deposit was amorphous and contained a significant amount of C. The Cr–C–S deposit plated in the bath containing thiosalicylic acid displayed a crystalline structure and was mainly composed of Cr, C, S, and oxygen. The presence of thiosalicylic acid in the bath apparently reduced the codeposition of C, which, in turn, enhanced the crystallinity of the Cr–C–S deposit. Furthermore, the codeposited S influenced the microstructure and properties of the deposits. The internal stress and population density of cracks of the deposit were reduced as more thiosalicylic acid was added in the trivalent Cr bath. Moreover, the corrosion potential was enhanced and the corrosion current density and the passivation current density were reduced with increasing bath thiosalicylic acid concentration. As a result, the crystalline, crack-free Cr–C–S deposit exhibited a better corrosion resistance than the amorphous Cr–C deposit.