가열 속도, 몰 공간속도, 질화반응온도 등 다양한 실험 조건을 변화하며 바나디움 산화물과 암모니아와의 승온 질화 반응을 통하여 바나디움 산화질화물을 제조하여 특성분석을 수행하였으며 제조된 바나디움 산화질화물 상에서 암모니아 분해반응의 촉매 활성을 검토하였다. 제조된 촉매의 물리·화학적 특성을 알아보기 위하여 N2 흡착분석, X-선 회절 분석(XRD), 수소 승온환원(H2-TPR), 산소 존재 하 승온산화 (TPO), 암모니아 탈착 (NH3-TPD), 투과전자현미경(TEM) 분석을 수행하였다. 340℃에서 5 m2 g-1의 낮은 비표면적을 갖는 V2O5의 환원에 의하여 V2O3으로의 변환은 미세기공 형성에 의해 115 m2 g-1 높은 비표면적 값을 보여주었으며 그 이상의 질화반응 온도가 증가함에 따라 소결현상에 의해 지속적인 비표면적의 감소를 초래하였다. 비표면적에 가장 큰 영향을 미치는 질화반응 변수는 반응온도였으며, 단일 상의 VNxOy의 x + y 값은 질화반응온도가 증가함에 따라 1.5에서 1.0으로 근접하였으며 680℃의 높은 반응온도 에서 입방 격자상수 a는 VN 값에 근접하였다. 본 실험 조건 중에 질화반응온도가 가장 높았던 680℃에서 암모니아 전환율은 93%로 나타났으며 비활성화는 관찰되지 않았다.

By varying various experimental conditions such as heating rate, molar hourly space velocity (MHSV), and nitridation reaction temperature, vanadium oxynitride was prepared through temperature programmed reduction/ nitridation reaction (TPRN) of vanadium pentoxide and ammonia, and characterization were performed. In order to investigate the physico-chemical properties of the prepared catalyst, N2 adsorption-desorption analysis, X-ray diffraction analysis (XRD), hydrogen temperature programmed reduction (H2-TPR), temperature programmed oxidation (TPO), ammonia temperature programmed desorption (NH3-TPD), transmission electron microscopy (TEM) was performed. Transformation of V2O5 with 5 m2 g-1 low specific surface area by reduction at 340℃ to V2O3 showed a high specific surface area value of 115 m2 g-1 by micropore formation. As the nitridation temperature increased beyond that, the specific surface area continued to decrease due to sintering. The nitridation reaction variable that had the greatest influence on the specific surface area was the reaction temperature, and the x + y value of VNxOy of a single phase approached from 1.5 to 1.0 as the nitridation reaction temperature increased. At a high reaction temperature of 680℃, the cubic lattice constant a was VN. close to the value. At 680℃, the highest nitridation temperature among the experimental conditions, the ammonia conversion rate was 93%, and no deactivation was observed.

NH3 decomposition Vanadium oxide Vanadium oxynitride Temperature programmed reduction/nitridation

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