1c:I[419806,["/_next/static/chunks/bb923814e1f4d2e9.js","/_next/static/chunks/dd3ee9f5b7716ca6.js","/_next/static/chunks/4204a0ae82542ca8.js","/_next/static/chunks/1270dead247da766.js","/_next/static/chunks/6e1aa89a642f40be.js","/_next/static/chunks/2d7aa753e81324a8.js","/_next/static/chunks/8ffd0b71567920d8.js","/_next/static/chunks/67ea6dfd21f16c5f.js","/_next/static/chunks/24eb4379f68013fd.js","/_next/static/chunks/b8cd775ffdf935bd.js","/_next/static/chunks/983103cd9eb7b428.js","/_next/static/chunks/263f2cdcb9aa2341.js","/_next/static/chunks/294b9525248c8e5f.js"],"default"] 1d:T42b,The origin and interpretation of the Raman features of amorphous (hydrogenated) carbon films deposited at room temperature in the region of 1000–1700 cm−1 is discussed in this paper. Possible interpretations of the linewidths, positions of the ‘‘G’’ graphite peak and ‘‘D’’ disordered peak, and their intensity ratios are examined using results obtained from magnetron sputtered and magnetic field enhanced plasma deposited films. It is shown that even small ‘‘clusters’’ of condensed benzene rings (cluster size below 20 Å) in carbon films can explain the observed Raman scattering. Besides the care that should be taken in the correct interpretation of Raman results, the utility of Raman scattering in obtaining an estimate of cluster sizes in amorphous (hydrogenated) carbon films is discussed. Carbon films prepared by magnetron sputtering show two additional Raman features at 1180 and 1490 cm−1 in addition to the G and D peaks. It is shown that a correlation exists between the 1180 cm−1 peak and the sp3 content in the films.1e:T43c,Hydrogen peroxide (H₂O₂) synthesis generally requires substantial postreaction purification. Here, we report a direct electrosynthesis strategy that delivers separate hydrogen (H₂) and oxygen (O₂) streams to an anode and cathode separated by a porous solid electrolyte, wherein the electrochemically generated H⁺ and HO₂ ^- recombine to form pure aqueous H₂O₂ solutions. By optimizing a functionalized carbon black catalyst for two-electron oxygen reduction, we achieved >90% selectivity for pure H₂O₂ at current densities up to 200 milliamperes per square centimeter, which represents an H₂O₂ productivity of 3.4 millimoles per square centimeter per hour (3660 moles per kilogram of catalyst per hour). A wide range of concentrations of pure H₂O₂ solutions up to 20 weight % could be obtained by tuning the water flow rate through the solid electrolyte, and the catalyst retained activity and selectivity for 100 hours.1f:T501,Product selectivity in multielectron electrocatalytic reactions is crucial to energy conversion efficiency and chemical production. However, a present practical drawback is the limited understanding of actual catalytic active sites. Here, using as a prototype single-atom catalysts (SACs) in acidic oxygen reduction reaction (ORR), we report the structure-property relationship of catalysts and show for the first time that molecular-level local structure, including first and second coordination spheres (CSs), rather than individual active atoms, synergistically determines the electrocatalytic response. ORR selectivity on Co-SACs can be tailored from a four-electron to a two-electron pathway by modifying first (N or/and O coordination) and second (C-O-C groups) CSs. Using combined theoretical predictions and experiments, including X-ray absorption fine structure analyses and in situ infrared spectroscopy, we confirm that the unique selectivity change originates from the structure-dependent shift of active sites from the center Co atom to the O-adjacent C atom. We show this optimizes the electronic structure and *OOH adsorption behavior on active sites to give the present "best" activity and selectivity of >95% for acidic H₂O₂ electrosynthesis.20:T5b3,

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