Abstract:The performance of Ni-Cu/Al 2 O 3 catalysts for steam reforming (SR) of gasoline to produce a hydrogen-rich gas mixture applied in a spark ignition (SI) engine was investigated at relatively low temperature. The structural and morphological features and catalysis activity were observed by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and temperature programmed reduction (TPR). The results showed that the addition of copper improved the dispersion of nickel and therefore facilitated the reduction of Ni at low temperature. The highest hydrogen selectivity of 70.6% is observed over the Ni-Cu/Al 2 O 3 catalysts at a steam/carbon ratio of 0.9. With Cu promotion, a gasoline conversion of 42.6% can be achieved at 550˝C, while with both Mo and Ce promotion, the gasoline conversions were 31.7% and 28.3%, respectively, higher than with the conventional Ni catalyst. On the other hand, initial durability testing showed that the conversion of gasoline over Ni-Cu/Al 2 O 3 catalysts slightly decreased after 30 h reaction time.

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Adhesion properties of CuO-CeO 2 =c-Al 2 O 3 layers on FeCrAl metallic substrate was investigated, where the hybrid preparation method between suspension and sol-gel is further combined with the mechanical milling process of the slurry. Poor coating adhesion was observed when the slurry is vigorously stirred, where the milled powders are agglomerated, and the stirring process hardly reduces the particle size. The combined method was found to significantly improve the adhesion property between the milled CuO-CeO 2 catalytic layer and the c-Al 2 O 3 washcoat, compared with the vigorous stirring of the slurry. The so-called ''over-milling'' phenomenon was also exhibited, where the elongated large particles are observed after sintering of the longer-milled powders, leading to the lowered adhesion quality.

The noble metals (Pt, Pd, Rh) supported on Cu-Ce mixed oxides with γ-Al 2 O 3 washcoat/FeCrAl substrate were investigated as catalytic performance of Three Way Catalysts (TWC) under simulated automotive exhaust feed gas. The structural, morphological features and catalytic activity were observed by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS) and GC-TCD (Varian CP-4900). The catalytic performance of noble metals (Pt, Rh, Pd) supported on Cu-Ce mixed oxides with γ-Al 2 O 3 washcoat/FeCrAl substrate was be compared with noble metals (Pt, Rh, Pd) supported on Ce-Zr mixed oxides with γ-Al 2 O 3 washcoat/FeCrAl substrate and only γ-Al 2 O 3 washcoat/FeCrAl substrate at various stoichiometric ratio of oxygen. The results showed that the addition of Cu-Ce mixed oxides improved CO oxidation reaction at lower temperature during stable lambda of 1, the highest CO conversion of 99% is observed for the noble metals (Pt, Pd, Rh) support on Cu-Ce with γ-Al 2 O 3 washcoat/FeCrAl substrate. The results also showed that, the addition of Cu-Ce mixed oxides promoted released oxygen, thus it improved strongly CO and C 3 H 8 conversion at lean oxygen stoichiometric operation.

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A blended learning environment is becoming more and more important in all subject areas, especially language education. This study is conducted to investigate the effects of blended EFL writing activities on students' perceptions and writing performance. This study employs both quantitative and qualitative research methods. An experiment (n=40) was conducted with two groups of English majors having the same curriculum, course-book, facilities for 15 weeks. The experimental group takes weekly writing activities online while the control group does not. After the experiment, the experiment group was surveyed (n=20) and interviewed (n=12). Independent samples T-tests show that the experimental group doing their writing activities in a blended environment performs better than the control group doing those activities on paper. The questionnaire and interview data further confirm that students have positive perceptions of EFL writing activities in blended classes. It is suggested that EFL students should be given online writing activities blended with their traditional sessions. Designing interesting writing tasks, providing good topics for discussion, creating a more interactive online environment that boosts collaborative learning are good ways to motivate students and improve student performance.

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