**4. Conclusions**

In this study, the effects of preparation parameters on catalyst properties were investigated on electrospun fibrous Ni/Al2O<sup>3</sup> catalysts. The catalyst prepared with the H2O/C2H5OH solvent mainly consisted of NiAl2O4, while the catalyst prepared with the DMF/C2H5OH solvent formed NiO due to Ni segregation. The catalytic performance is mainly contributed by the Ni from NiAl2O<sup>4</sup> reduction, and therefore the catalytic activity of the catalyst prepared with the H2O/C2H5OH solvent was higher than that of the catalyst prepared with the DMF/C2H5OH solvent. The metal ion content affects catalyst composition, microstructure, reducibility and dispersion and therefore catalytic performance during the POM. The C30 catalyst had the highest catalytic performance. In addition, the higher calcination temperature produced the larger Ni particles due to the larger crystal size of NiAl2O4, which required a high reduction temperature. Therefore, the catalytic activity during the POM decreased with the increase of calcination temperature. Finally, it has been confirmed that the fibrous Ni/Al2O<sup>3</sup> catalysts can achieve high syngas yields through the POM owing to the fibrous structure.

**Author Contributions:** Conceptualization, Y.M. (Yuyao Ma) and D.D.; methodology, Y.M. (Yuyao Ma), Y.M. (Yuxia Ma), M.L. and Y.C.; software, Y.M. (Yuyao Ma); validation, X.H., Z.Y. and D.D.; formal analysis, Y.M. (Yuyao Ma), Y.M. (Yuxia Ma) and D.D.; investigation, Y.M. (Yuyao Ma), Y.M. (Yuxia Ma), M.L. and Y.C.; resources, D.D.; data curation, Y.M. (Yuyao Ma), M.L. and Y.C.; writing—original draft preparation, Y.M. (Yuyao Ma); writing—review and editing, D.D.; visualization, X.H., Z.Y. and D.D.; supervision, X.H., Z.Y. and D.D.; project administration, D.D.; funding acquisition, D.D.

**Funding:** This research was funded by Natural Science Foundation of Shandong Province (ZR2017MEM022) and Shandong Province Key Research and Development Program (2018GGX102037).

**Acknowledgments:** D. H. Dong acknowledges the startup funding provided by the University of Jinan. The study is a part of the projects of Natural Science Foundation of Shandong Province (ZR2017MEM022) and Shandong Province Key Research and Development Program (2018GGX102037).

**Conflicts of Interest:** The authors declare no conflict of interest. The funder played a decisive role in the design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript and in the decision to publish the results.

### **References**


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