Zhang Xuefeng, Yan Qiangu, Li Jinghao, Zhang Jilei, Cai Zhiyong
Department of Sustainable Bioproducts, Mississippi State University, Mississippi State, MS 39762, USA.
U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI 53726, USA.
Materials (Basel). 2018 Jan 15;11(1):139. doi: 10.3390/ma11010139.
Effects of physical and chemical states of iron-based catalysts on the formation of carbon-encapsulated iron nanoparticles (CEINs) synthesized thermally from kraft lignin were investigated. Experimental results indicated that if solution-based iron nitrate (FeN) was used as an iron source for the catalyst, CEINs observed were α-Fe and γ-Fe-based cores encapsulated by few layers graphitic-carbon (mostly 1-5 layers) and the majority of these CEINs were embedded in amorphous carbon matrix. The formation of graphitic-carbon shells is believed based on the dissolution and precipitation mechanism of amorphous carbon acting as the carbon source. If solid-based iron nanoparticles (FePs) were used as the catalyst, CEINs observed were α-Fe, γ-Fe, and Fe₃C-based cores encapsulated with tangled graphitic-carbon nanoribbons and carbon tubules and the majority of these CEINs were found along the edge of amorphous carbon matrix. The growth of tangled graphitic-carbon nanoribbons and carbon tubules is based on a chemical vapor decomposition process, i.e., the carbonaceous gases from kraft lignin decomposition served as the carbon source.
研究了铁基催化剂的物理和化学状态对由硫酸盐木质素热合成的碳包覆铁纳米颗粒（CEINs）形成的影响。实验结果表明，如果将基于溶液的硝酸铁（FeN）用作催化剂的铁源，观察到的CEINs是由几层石墨碳（大多为1 - 5层）包覆的α-Fe和γ-Fe基核，并且这些CEINs中的大多数嵌入非晶碳基质中。基于作为碳源的非晶碳的溶解和沉淀机制，认为形成了石墨碳壳。如果将基于固体的铁纳米颗粒（FePs）用作催化剂，观察到的CEINs是由缠结的石墨碳纳米带和碳管包覆的α-Fe、γ-Fe和Fe₃C基核，并且这些CEINs中的大多数沿着非晶碳基质的边缘发现。缠结的石墨碳纳米带和碳管的生长基于化学气相分解过程，即来自硫酸盐木质素分解的含碳气体用作碳源。
