In this study, we explored the feasibility of using base metal catalysts for three-way catalysis. The catalysts contain up to three base metals that were chosen to replace or reduce use of platinum group metals (Rh, Pd, and Pt). The aim was to develop catalysts with high activities at low temperatures having robustness against oxygen concentration fluctuations. Various base metal catalysts supported on alumina [10 wt % X/Al2O3 (X = Fe, Co, Ni, or Cu), 10 wt % CuY/Al2O3 (Y = Mn, Fe, Co, or Ni; Cu/Y = 1:1 in atomic ratio), and 10 wt % CuNi–5 wt % Z/Al2O3 (Z = Mn, Fe, or Co; Cu/Ni = 1:1 in atomic ratio)] were tested by temperature-programmed reaction in NO–CO–C3H6–O2 flow and under fluctuating oxygen concentration conditions. We found that the rate of reduction of NO over the 10 wt % CuNi–5 wt % Fe/Al2O3 catalyst in the low-temperature region was comparable to that of 1 wt % Pt/Al2O3, and this catalyst was also tolerant to oxidative conditions to some extent. Ex situ characterization of the catalysts before and after the three-way catalytic reaction was carried out via powder X-ray diffraction, X-ray absorption spectroscopy, scanning transmission electron microscopy with an energy-dispersive X-ray spectrometer, and in situ diffuse reflectance infrared Fourier transform measurements and revealed that the presence of Fe species resulted in the significantly improved oxidation of C3H6 and, thus, an increased rate of reduction of NO.

This study reports a cobalt-catalyzed synthesis of cyclobutenes using alkynes and acrylates bearing a leaving group at the α position. The cyclobutene formation was facilitated by an appropriate proton source. In the presence of a Lewis acid, acetonitrile participated in the reaction, affording the corresponding functionalized cyclobutenes.[a] Prof.

Cyclobutene Ring! A cobalt complex with dppf as the ligand catalyzed the synthesis of cyclobutenes from alkynes and acrylates bearing a leaving group at the α position. The formation of cyclobutenes was facilitated by a suitable proton source. In the presence of a Lewis acid, acetonitrile participated in the reaction, affording the corresponding acetylated cyclobutenes. More information can be found in the Communication by Tetsuaki Fujihara, Yasushi Tsuji et al. on page 2456 in Issue 12, 2018 (DOI: 10.1002/ajoc.201800561).