CAJ | 학술논문

为了研究氧化铈(YDC)材料的氧化还原性能,通过水溶液体系中沉淀反应平衡的计算,研究了Y3＋、Ce3＋在水溶液体系中共沉淀的 pH 值条件,并制备了 Ce1-x Yx O 2-δ(x ＝0,15％,25％)纳米粉体,平均晶粒尺寸在12 nm 左右。通过 O 2-TPD 研究了 Ce1-x Yx O 2-δ纳米粉体在室温~1000℃的氧气的脱附行为,发现随着 Y2 O 3掺杂量增加,氧脱附峰面积增大,但脱附氧的起始温度提高,说明 Y2 O 3的掺杂使样品中的氧空位增加,增加了氧的脱附量。通过 H 2-TPR研究了 Ce1-x Yx O 2-δ纳米粉体在200~1000℃条件下的氢气还原能力,发现随着 Y2 O 3掺杂量增加,在450~650℃,Ce1-x Yx O 2-δ纳米粉体消耗 H 2峰强度逐渐增大,说明 Ce1-x Yx O 2-δ的抗还原性能提高；在750~950℃,CeO 2纳米粉体的消耗 H 2峰强度逐渐减小,说明 CeO 2抗还原的能力逐渐降低。通过 O-1s 和Ce3d XPS 能谱分析结果可知,随着 Y2 O 3掺杂量增加,Ce1-x Yx O 2-δ纳米粉体的晶格氧峰和吸附氧峰的强度降低,证明了在加热过程中,Ce1-x Yx O 2-δ的氧气脱附量逐渐增大；相对在空气条件下加热处理的样品,在10％ H 2/Ar 混合气体条件下加热处理后,Ce1-x Yx O 2-δ纳米粉体中有部分的 Ce4＋被还原为 Ce3＋。
위료연구양화시(YDC)재료적양화환원성능,통과수용액체계중침정반응평형적계산,연구료Y3＋、Ce3＋재수용액체계중공침정적 pH 치조건,병제비료 Ce1-x Yx O 2-δ(x ＝0,15％,25％)납미분체,평균정립척촌재12 nm 좌우。통과 O 2-TPD 연구료 Ce1-x Yx O 2-δ납미분체재실온~1000℃적양기적탈부행위,발현수착 Y2 O 3참잡량증가,양탈부봉면적증대,단탈부양적기시온도제고,설명 Y2 O 3적참잡사양품중적양공위증가,증가료양적탈부량。통과 H 2-TPR연구료 Ce1-x Yx O 2-δ납미분체재200~1000℃조건하적경기환원능력,발현수착 Y2 O 3참잡량증가,재450~650℃,Ce1-x Yx O 2-δ납미분체소모 H 2봉강도축점증대,설명 Ce1-x Yx O 2-δ적항환원성능제고；재750~950℃,CeO 2납미분체적소모 H 2봉강도축점감소,설명 CeO 2항환원적능력축점강저。통과 O-1s 화Ce3d XPS 능보분석결과가지,수착 Y2 O 3참잡량증가,Ce1-x Yx O 2-δ납미분체적정격양봉화흡부양봉적강도강저,증명료재가열과정중,Ce1-x Yx O 2-δ적양기탈부량축점증대；상대재공기조건하가열처리적양품,재10％ H 2/Ar 혼합기체조건하가열처리후,Ce1-x Yx O 2-δ납미분체중유부분적 Ce4＋피환원위 Ce3＋。
To investigate the redox property of Ce1 -x Yx O 2 -δ(x =0,0.15,0.25 YDC)nanopowder,the YDC nanopowder with average crystal size around 12 nm was prepared by co-precipitation method.The pH value of Y3 + ,Ce3 + co-precipitation was studied in aqueous solution by calculation of precipitation equilibrium.Through the O 2-TPD study at RT-1 000 ℃,it was found that the oxygen desorption increased at higher initial oxidation temperature as results of oxygen vacancies increment and ceria reduction by Y2 O 3 doping.The reducing proper-ty of YDC was investigated by H 2-TPR at 200-1 000 ℃.The Y2 O 3 dopant enhanced the anti-reducing property of YDC at 450-650 ℃.While the H 2 consumption peak decreased with the Y2 O 3 dopant increased at 750-950 ℃, the results suggested the decrease of YDC reducing property.Compared the O1s and Ce3d spectrums of XPS re-sults,the peaks of lattice oxygen and oxygen desorption increased with the Y2 O 3 dopant increased,that showed the oxygen desorption of Ce1 -x Yx O 2 -δ nanopowder increased in the heating process.And it was found that Ce4+was partly transformed to Ce3 + by Y2 O 3 doping after heat treatment at air or 10%H 2/Ar atmosphere.