Liquid hourly space velocity (LHSV) is a critical factor in steam reforming as it not only determines process capacity of reformer, but also affect the properties of the coke formed via impacting the activation of the reactants and the formation of the products. In this study, the impacts of LHSV on the properties of the coke formed in steam reforming of acetic acid over Ni/SBA-15 catalyst were investigated. The results indicated that the increasing LHSV promoted the formation of the gaseous by-products and accelerated coking, as the low residence time was not conducive for activation of steam. The coke formed at the higher LHSV was more aromatic and have more fused but defective ring structures. Furthermore, at the low steam ratio in reactants, the high LHSV could also promoted the retainment of the carbonyl functionality in the coke. These phenomena are mainly due to the higher abundance of the organic species on surface of the catalyst under the high LHSV. In addition, not only the cavity of the carbon nanotube but also other morphologies the coke such as carbon nanofiber, bamboo-like structure and string beads-like structure was closely related to the LHSV, as LHSV impacted the reaction intermediates formed and further on the precursors of the coke.

液时空速（LHSV）是蒸汽重整的关键因素，因为它不仅决定重整器的工艺能力，而且还通过影响反应物的活化和产物的形成而影响所形成的焦炭的性能。在这项研究中，研究了LHSV对在Ni / SBA-15催化剂上乙酸蒸汽重整乙酸中形成的焦炭性能的影响。结果表明，LHSV的增加促进了气态副产物的形成并加速了焦化，因为停留时间短不利于蒸汽的活化。在较高的LHSV下形成的焦炭更芳香，具有更稠密但有缺陷的环结构。此外，在反应物中蒸汽比率低的情况下，高LHSV还可以促进羰基官能度在焦炭中的保留。这些现象主要是由于在高LHSV下催化剂表面有机物的含量较高。此外，不仅碳纳米管的腔体，而且其他形态的焦炭（如碳纳米纤维，竹样结构和串珠状结构）都与LHSV密切相关，因为LHSV影响了形成的反应中间体，进而影响了焦炭的前体。