Zinc Blende CoO as an Efficient CO Nondissociative Adsorption Site for Direct Synthesis of Higher Alcohols from Syngas
Zhuoshi Li, Guangyuan Luo, Zhiwei Hu, Xiaofeng Pei, Zhuang Zeng, Shaoxia Guo, Jing Lv, Shouying Huang, Yue Wang, Xinbin Ma
Abstract
Monometallic Co 0 –Co δ+ catalysts have shown considerable potential in higher alcohol synthesis (HAS) direct from syngas, however, the alcohol selectivity and catalyst stability still need to be promoted. Here, we prepared a series of cobalt silicate hydroxide-derived catalysts and surprisingly obtained tetrahedrally coordinated zinc blende CoO (Z-CoO) during reduction and reaction. The nanoscale close interacted Co 0 -Z-CoO achieved an ROH selectivity of 64.4%, a higher alcohol (HA) selectivity of 43.6%, and a space time yield (STY) toward HA of 42.0 mmol·g Co –1 ·h –1, which outperformed most of the reported Co-based HAS catalysts. In addition, as a contrast, the commonly obtained rocksalt CoO (R-CoO) with octahedral structure was prepared. It is proved that Z-CoO serves as the CO nondissociative adsorption site, which exhibits a much stronger adsorption capability compared to R-CoO and Co 2 C, greatly facilitating the alcohol formation. Moreover, unlike the R-CoO, there were barely no phase transition of Z-CoO during HAS reaction, contributing to the catalyst stability over 550 h reaction. This work offers a facile preparation method and insights of zinc blende CoO as promising high-performance active sites for HAS.