Liquid organic hydrogen carriers (LOHCs) offer a promising solution for global hydrogen infrastructure, but their practical application faces two key challenges: sluggish dehydrogenation processes and the reliance on catalysts with high noble metal loadings. This study presents a scalable approach to reduce noble metal usage while maintaining high catalytic activity. We synthesized an ultralow Pt content (0.
View Article and Find Full Text PDFHydrogen has received enormous attention as a clean fuel with its high specific energy (HHV=142 MJ kg). To apply hydrogen as a practically available energy vector, the direct production of high-pressure hydrogen with high purity is pivotal as it allows for circumventing the mechanical compression process. Recently, the concept of utilizing sodium borohydride (SBH) dehydrogenation as a chemical compressor that can generate high-pressure hydrogen gas was demonstrated by adopting formic acid as an acid catalyst.
View Article and Find Full Text PDFAlthough often overlooked in anode research, the anode's initial Coulombic efficiency (ICE) is a crucial factor dictating the energy density of a practical Li-ion battery. For next-generation anodes, a blend of graphite and Si/SiO represents the most practical way to balance capacity and cycle life, but its low ICE limits its commercial viability. Here, we develop a chemical prelithiation method to maximize the ICE of the blend anodes using a reductive Li-arene complex solution of regulated solvation power, which enables a full cell to exhibit a near-ideal energy density.
View Article and Find Full Text PDFBimetallic PdNi alloys supported on nitrogen-doped carbon (PdNi/N-C, x = 0.37, 1.3 and 3.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2021
We report the fabrication and catalytic performance evaluation of highly active and stable nickel (Ni)-based structured catalysts for ammonia dehydrogenation with nearly complete conversion using nonprecious metal catalysts. Low-temperature chemical alloying (LTCA) followed by selective aluminum (Al) dealloying was utilized to synthesize foam-type structured catalysts ready for implementation in commercial-scale catalytic reactors. The crystalline phases of Ni-Al alloy (NiAl, NiAl, or both) in the near-surface layer were controlled by tuning the alloying time.
View Article and Find Full Text PDFPrelithiation is of great interest to Li-ion battery manufacturers as a strategy for compensating for the loss of active Li during initial cycling of a battery, which would otherwise degrade its available energy density. Solution-based chemical prelithiation using a reductive chemical promises unparalleled reaction homogeneity and simplicity. However, the chemicals applied so far cannot dope active Li in Si-based high-capacity anodes but merely form solid-electrolyte interphases, leading to only partial mitigation of the cycle irreversibility.
View Article and Find Full Text PDFFormic acid (HCOOH, FA) has long been considered as a promising hydrogen-storage material due to its efficient hydrogen release under mild conditions. In this work, FA decomposes to generate CO and H selectively in the presence of aqueous Pd complex solutions at 333 K. Pd(NO ) was the most effective in generating H among various Pd complexes explored.
View Article and Find Full Text PDFAlkyne cross-metathesis of molybdenum carbyne complex [TolC≡Mo(OCCH(CF))]·DME with 2 equiv of functional ynamines or ynamides yields the primary cross-metathesis product with high regioselectivity (>98%) along with a molybdenum metallacyclobutadiene complex. NMR and X-ray crystal structure analysis reveals that ynamides derived from 1-(phenylethynyl)pyrrolidin-2-one selectively cleave the propagating molybdenum species in the ring-opening alkyne metathesis polymerization (ROAMP) of ring-strained 3,8-dihexyloxy-5,6-dihydro-11,12-didehydrodibenzo[a,e][8]annulene and irreversibly deactivate the diamagnetic molybdenum metallacyclobutadiene complex through a multidentate chelate binding mode. The chain termination of living ROAMP with substituted ethynylpyrrolidin-2-ones selectively transfers a functional end-group to the polymer chain, giving access to telechelic polymers.
View Article and Find Full Text PDFFour alternating AB copolymers have been prepared through ring-opening metathesis polymerization (ROMP) with Mo(NR)(CHCMe2Ph)[OCMe(CF3)2]2 initiators (R = 2,6-Me2C6H3 (1) or 2,6-i-Pr2C6H3 (2)). The A:B monomer pairs copolymerized by 1 are cyclooctene (A):2,3-dicarbomethoxy-7-isopropylidenenorbornadiene (B), cycloheptene (A'):dimethylspiro[bicyclo[2.2.
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