The generation of tar in biomass gasification is highly undesirable since the condensation and agglomeration of tar causes clogging and contamination of downstream equipment, leading to low energy efficiency and high maintenance cost. Currently, the most widely used methods for tar reforming are catalytic reforming and plasma reforming. However, the main drawbacks for these two processes are: (i) the rapid catalyst deactivation caused by poisoning, sintering and coke deposition for catalytic reforming, and (ii) low energy efficiency, low selectivity of syngas and the formation of undesirable byproducts for plasma reforming. Recently, therefore, the hybrid plasma-catalysis system has attracted much attention for tar reforming, since it can overcome the above-mentioned drawbacks and generate a synergy effect. The addition of catalyst in plasma could change the discharge properties of plasma, and the plasma could also modify the catalyst property and change the status of reactants. At present, very few review articles have reported and compared the performances of tar reforming in the plasma-only, catalysis-only and hybrid plasma-catalysis system. Therefore, this review paper focus on: (i) the deactivation characteristics and modification methods of steam-reforming catalysts, as well as the mechanism of tar catalytic reforming; (ii) the performance of tar reforming in various plasma reactors and the reaction mechanism based on the analysis of byproducts and energetic plasma species; and (iii) the possible synergistic effect of plasma and heterogeneous catalyst in a hybrid plasma-catalysis system caused by the multiple interactions of plasma and catalysts.

由于焦油的冷凝和团聚导致下游设备的堵塞和污染，导致生物质气化过程中焦油的产生是非常不希望的，从而导致低能源效率和高维护成本。当前，最广泛使用的焦油重整方法是催化重整和等离子体重整。但是，这两种方法的主要缺点是：（i）由中毒，烧结和焦炭沉积以进行催化重整而导致的催化剂快速失活，以及（ii）能源效率低，合成气选择性低以及形成了不良的等离子体副产物重整。因此，最近，由于混合等离子体催化系统可以克服上述缺点并产生协同作用，因此引起了焦油重整的广泛关注。在等离子体中添加催化剂可以改变等离子体的放电性能，并且等离子体也可以改变催化剂的性能并改变反应物的状态。目前，很少有评论文章报道并比较了仅等离子体，仅催化和混合等离子体催化系统中焦油重整的性能。因此，本综述着重于：（i）蒸汽重整催化剂的失活特性和改性方法，以及焦油催化重整的机理；（ii）在分析副产物和高能等离子体种类的基础上，在各种等离子体反应器中进行焦油重整以及反应机理；