Catalytic transformation of CH4 under a mild condition is significant for efficient utilization of shale gas under the circumstance of switching raw materials of chemical industries to shale gas. Here, we report the transformation of CH4 to acetic acid and methanol through coupling of CH4, CO and O2 on single-site Rh1O5 anchored in microporous aluminosilicates in solution at ≤150 °C. The activity of these singly dispersed precious metal sites for production of organic oxygenates can reach about 0.10 acetic acid molecules on a Rh1O5 site per second at 150 °C with a selectivity of ~70% for production of acetic acid. It is higher than the activity of free Rh cations by >1000 times. Computational studies suggest that the first C–H bond of CH4 is activated by Rh1O5 anchored on the wall of micropores of ZSM-5; the formed CH3 then couples with CO and OH, to produce acetic acid over a low activation barrier.

Simultaneous improvements in oxygen reduction reaction (ORR) activity and long-term durability of Ptbased cathode catalysts are indispensable for the development of next-generation polymer electrolyte fuel cells but are still a major dilemma. We present a robust octahedral core−shell PtNi x /C electrocatalyst with high ORR performance (mass activity and surface specific activity 6.8−16.9 and 20.3−24.0 times larger than those of Pt/C, respectively) and durability (negligible loss after 10000 accelerated durability test (ADT) cycles). The key factors of the robust octahedral nanostructure (core−shell Pt 73 Ni 27 /C) responsible for the remarkable activity and durability were found to be three continuous Pt skin layers with 2.0−3.6% compressive strain, concave facet arrangements (concave defects and high coordination), a symmetric Pt/Ni distribution, and a Pt 67 Ni 33 intermetallic core, as found by STEM-EDS, in situ XAFS, XPS, etc. The robust core−shell Pt 73 Ni 27 /C was produced by the partial release of the stress, Pt/Ni rearrangement, and dimension reduction of an as-synthesized octahedral Pt 50 Ni 50 /C with 3.6−6.7% compressive Pt skin layers by Ni leaching during the activation process. The present results on the tailored synthesis of the PtNi x structure and composition and the better control of the robust catalytic architecture renew the current knowledge and viewpoint for instability of octahedral PtNi x /C samples to provide a new insight into the development of next-generation PEFC cathode catalysts. KEYWORDS: robust octahedral core−shell PtNi x /C electrocatalyst, polymer electrolyte fuel cell, high performance and durability, continuous, compressive and concave Pt skin layers, structural and electronic property, in situ XAFS/STEM-EDS/XPS/ICP-AES

We have succeeded in simultaneous operando time-resolved quick X-ray absorption fine structure (QXAFS)–X-ray diffraction (XRD) measurements at each acquisition time of 20 ms for a Pt/C cathode catalyst in a polymer electrolyte fuel cell (PEFC), while measuring the current/charge of the PEFC during the transient voltage cyclic processes (0.4 VRHE → 1.4 VRHE → 0.4 VRHE) under H2(anode)–N2(cathode). The rate constants for Pt–O bond formation/dissociation, Pt charging/discharging, Pt–Pt bond dissociation/reformation, and decrease/increase of Pt metallic-phase core size under the transient potential operations were determined by the combined time-resolved QXAFS–XRD technique. The present study provides a new insight into the transient-response reaction mechanism and structural transformation in the Pt surface layer and bulk, which are relevant to the origin of PEFC activity and durability as key issues for the development of next-generation PEFCs.

We have designed a structure for a 2×2 silica-based optical waveguide switch that is based on a thermocapillarity effect. This switch can use the reflection walls on both sides of the slit, because the Goos–Hänchen shift effect was taken into account when the structure of the waveguides and the slit was designed. This switch can provide a cross/bar function through a single element, and the measured reflection losses in the reflection walls on both sides of the slit were consistent. The loss was comparable to the insertion loss of a Mach–Zender-interferometer-type thermo-optic switch.

We have developed an ambient pressure hard-X-ray photoelectron spectroscopic system equipped with a differential pumping system at BL36XU of SPring-8. Photoelectron spectra from a Au(111) surface were recorded using excitation light of 8 keV focused to 20 × 20 µm2 and adopting an aperture diameter of 30 µm at the entrance of the electron lens and a working distance of 60 µm. The Au 4f and 3d5/2 spectra were measured by increasing the ambient pressure from 1 Pa to atmospheric pressure and demonstrated that the instrument is capable of measuring the photoelectron spectrum under atmospheric pressure.