分级多孔金-铜薄膜对苯甲醇的催化氧化
Hierarchically porous Au-Cu thin films as catalysts for aerobic oxidation of benzyl alcohol

采用合金/去合金法，在金-铜合金线表面制备了分级多孔金-铜薄膜结构(Hierarchically porous Au-Cu thin films，HPAFs)。该分级多孔结构是由微米级的大尺寸孔道-系带和纳米级小尺寸系带-孔道构成。通过对电沉积、退火处理及腐蚀条件的控制可以调控表面多孔薄膜层的厚度、结构以及组成。研究结果表明，脱合金处理残留的铜在富金的系带上形成了金主导的AuCu合金-CuOx异质结构，其可以有效地促进分子氧的活化，而分级多孔结构有利于反应物分子在孔内的扩散传质，从而赋予HPAFs催化剂对苯甲醇分子氧氧化反应高催化活性。
Hierarchically porous Au-Cu thin films (HPAFs) fabricated on Au-Cu alloy wire surface by an alloying/dealloying process are reported, which exhibit superior catalytic performance for benzyl alcohol aerobic oxidation. The porous structure is composed of large-sized ligament channels (several micrometers) coupled with small-sized ligament pores (tens of nanometers), which interpenetrate in the big architecture. The morphology and composition of HPAFs can be easily tailored by altering electrodeposition, pretreatment and corrosion conditions. The characterization reveals that Cu residue in Au-rich ligament created an Au dominated AuCu(alloy)-CuOx heterostruture, which is highly active for molecular oxygen activation and favorable for benzyl alcohol aerobic oxidation. Furthermore, the surface thin-layer hierarchically porous structure of HPAFs enables the decrease in the internal diffusion resistance, and therefore further improves their catalytic performance where the pore diffusion is the rate-limiting step.