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A novel Fe–Ni–Ti composite oxide prepared via the hydrothermal method has been developed for the selective catalytic reduction of NO x with NH3. This environmentally benign catalyst showed high activity and excellent selectivity to N2, which is superior to that of Fe–Ti and Ni–Ti catalysts. Catalyst characterization results revealed that over Fe–Ni–Ti catalyst the dual redox cycles (Fe3+ + Ni2+ ↔ Fe2+ + Ni3+, Ti4+ + Ni2+ ↔ Ti3+ + Ni3+) are crucial for the enhanced activity. The synergetic effect among Fe, Ni, and Ti leads to not only the increased redox property, but also improved surface acidity. DRIFT experiments demonstrated that more reactive NH3/NH4 + and M-NO2 nitro species formed over Fe–Ni–Ti catalyst, thus resulting in the efficiently catalytic removal of NO x .

A series of Fe2(SO4)3/CeO2 composite oxide catalysts were fabricated for the selective catalytic reduction of NO x by NH3 (NH3–SCR). Compared with CeO2 and Fe2(SO4)3 catalysts, Fe2(SO4)3/CeO2 exhibited much higher activity and enhanced N2 selectivity. On the basis of the results of characterization, it can be seen that both the reducibility and the surface acidity of Fe2(SO4)3/CeO2 have been enhanced remarkably, which is ascribed to the synergetic effect among Fe, Ce, and SO4 2–. In-situ DRIFTS research demonstrated that over Fe2(SO4)3/CeO2, the generation of inactive nitrate was suppressed. Meanwhile, the adsorption and activation of NH3 was remarkably enhanced. Consequently, superior NH3–SCR catalytic performance was achieved over Fe2(SO4)3/CeO2 catalyst.

Friction stir welding of 1016 pure aluminum and T2 pure copper with 2 mm thickness was carried out in the form of lap welding of copper on the upper side and aluminum on the lower side. The growth of interface microstructure between 1016 pure aluminum and T2 pure copper welded by friction stir welding was studied. The growth mechanism of the intermetallic compound (IMC) layer in the Cu-Al lap joint was revealed by annealing at 300, 350, 400 °C. The intermetallic compound (IMC) layer in the lap joint grows again during annealing, and only the original structure of the intermetallic compound (IMC) layer grows at lower annealing temperature and holding time. At higher annealing temperature and holding time, the original structure of intermetallic compound (IMC) layer no longer grows, and a new layered structure appears in the middle of the original structure. There is a gradient change of microhardness in the nugget zone. With different holding times, different softening phenomena appear in the metals on both sides of copper and aluminum. When the hardness decreases to a certain extent, it will not continue to decrease with the increase of holding time. When the annealing temperature is 350 °C and 400 °C, the strength of the tensile sample increases first and then decreases with the increase of holding time. At the interface of Cu-Al, the fracture runs through the whole intermetallic compound (IMC) layer.