High power RF energy supplied to a reaction chamber at a resonant frequency is used to break the covalent bonds of a hydrocarbon material without heat. An RF signal generator may be used to supply RF energy to a resonant ring through a four port coupler. The phase of the RF energy ...
Dynamic bonds offer unique advantages of adaptability and selectivity, yet, supramolecular electrocatalysts specifically tailored for 2e− pathway remain unexplored. Here, the authors report a host-guest strategy that employs dynamic bonds to adjust electronic states through dual-channel regulation. Hongni...
Forachemicalreactiontooccur,acovalentbondmustbebroken.Thisrequiresenergy.Oncetheatomsarepartiallyapart,theycanbindtonewatomsformingstrongerbonds.Onlyasmallnumberofreactionswilloccuratphysiologicaltemperaturesintheabsenceofacatalyst.Theenergyrequiredtobreaktheoldcovalentbondsinachemicalreactioniscalledtheactivationenergy.The...
The more stable a bond, the greater the amount of energy that is required to break it. As expected, different bonds exhibit different bond-dissociation energies. Table 3-2 presents some bond-dissociation energies for some commonly encountered bonds in organic chemistry [6–8]. It is important...
Metal-oxoacid-mediated oxyhydroxide with proton acceptor to break adsorption energy scaling relation for efficient oxygen evolution Rongrong Zhang, Beibei Guo, Lun Pan, Zhen-Feng Huang, Chengxiang Shi, Xiangwen Zhang, Ji-Jun Zou 2023, 80(5): 594-602. DOI: 10.1016/j.jechem.2023.02.024 ...
When fracture occurs and generates new surface(s) a certain amount of energy is required. This energy is a combination of the energy required to break atomic bonds along the fracture path as well as energy dissipated in the region of high stress around the tip of a crack. Because of the ...
However, the extremely strong N≡N triple-bonds in nitrogen molecules and the competitive hydrogen evolution reaction lead to the unsatis-factory NH3 yield and the Faradaic efficiency (FE) of eNRR, making the development of high-performance catalysts with adequate active sites and high selectivity ...
sodium chloride, the solid is more stable than the gaseous ions by 787 kJ mol-1, and that is a measure of the strength of the attractions between the ions in the solid. Remember that energy (in this case heat energy) is given out when bonds are made, and is needed to break bonds....
These results are consistent with a mechanism in which detonation of RDX is initiated by mechanical generation of CT pairs that localize at vacancies, recombine, and release energy sufficient to break bonds; crystals of molecules with lower dipole moments should be less sensitive. 展开 ...
However, significant challenges remain regarding the activity and stability of nickel-based catalysts, which are most widely used in alcohol SR processes due to their affordability and ability to break C-C, O-H and C-H bonds, yet are prone to rapid deactivation primarily caused by coke ...