【摘要】 采用NaBH₄还原法将纳米金属Cu负载在Y₂O₃上.通过X射线衍射（XRD）、X射线光电子能谱（XPS）、透射电子显微镜（TEM）和测定氢氧根在Y₂O₃和Cu上的吸附等手段对样品进行了表征.结果表明,Y₂O₃表面存在一层薄的Y（OH）3,能优先吸附OH-使其在Y₂O₃表面"富集";金属Cu以纳米粒子形式负载在Y₂O₃上.在碱性甲醛溶液中考察了Y₂O₃负载Cu（Cu/Y₂O₃）的催化性能.结果表明,在低碱度条件下,相对于未负载纳米Cu的Y₂O₃,Cu/Y₂O₃具有较高的产氢活性.当氢氧化钠浓度为0.050 mol/L时,在氮气气氛下Cu/Y₂O₃产氢量约为未负载纳米Cu的7.8倍;而在空气气氛下约为4.3倍.在2种气氛下,Cu/Y₂O₃产氢的最佳氢氧化钠浓度均为0.25 mol/L.这可归结为Y₂O₃表面对OH-的"富集"效应,使其表面产生更多的活性物种CH2（OH）O-（甲二醇负离子）.相对于未负载纳米Cu的Y₂O₃,Y₂O₃负载Cu提高了催化剂的稳定性,其原因是Y₂O₃负载阻止了Cu粒子在反应过程的生长.更多还原

【Abstract】 Nano metal Cu was loaded on Y₂O₃ by NaBH₄ reduction method. The sample was characterized by X-ray diffraction（ XRD）,X-ray photoelectron spectroscopy（ XPS）,transmission electron microscopy（ TEM）and adsorption measurement of OH-on Y₂O₃ and Cu. The results show that there is a thin layer of Y（ OH）3on the surface of Y₂O₃,which can preferentially adsorb OH-,that is,"enrichment"of OH-on Y₂O₃; metal Cu was loaded on Y₂O₃ in the form of nano particles. The performance of Cu supported on Y₂O₃（ Cu/Y₂O₃）catalyst was investigated in alkaline formaldehyde solution. The results show that under low alkalinity,Cu/Y₂O₃ exhibits higher activity for hydrogen production than unloaded nano metal Cu. When the concentration of Na OH is 0. 050 mol/L,the hydrogen amount produced over Cu/Y₂O₃ is 7. 8 times as high as that over nano Cu under N2 atmosphere,whereas the former is 4. 3 times as high as the latter under air atmosphere. The optimal Na OH concentration for hydrogen production over Cu/Y₂O₃ is 0. 25 mol/L under both atmospheres. The results can be attributed to "enrichment"effect of OH-on Y₂O₃,leading to production of the higher concentration of active CH2（ OH） O-（ formaldehyde anion） species on Y₂O₃. The stability of Cu/Y₂O₃ is improved compared with that of unloaded nano Cu. The reason is that the load of Cu on Y₂O₃ prevents growth of Cu particles during the reaction.更多还原