Chanerika Revana, Shozi Mzamo L, Friedrich Holger B
School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa.
ACS Omega. 2022 Jan 26;7(5):4026-4040. doi: 10.1021/acsomega.1c05231. eCollection 2022 Feb 8.
Catalysts featuring 2, 5, and 10 wt % silver supported on alumina were prepared by the deposition precipitation method and activated under hydrogen. All catalysts were characterized by Brunauer-Emmett-Teller (BET) measurements, inductively coupled plasma-optical emission spectrometry (ICP-OES), backscattered electron scanning electron microscopy (BSE-SEM), high-resolution transmission electron microscopy (HR-TEM), hydrogen-temperature-programmed reduction (H-TPR), H-chemisorption, thermogravimetric analysis (TGA), infrared (IR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, and isopropylamine (IPA) TPD and evaluated in a continuous plug flow fixed-bed reactor. Metal nanoparticles with average sizes of 4.5, 11.5, and 21.1 nm were identified by HR-TEM for the 2, 5, and 10 wt % Ag/AlO catalysts, respectively. A conversion of 99% was observed for 1-octyne over particles between 10 and 15 nm in size, with stable operation up to 24 h (decreasing thereafter) at a temperature of 140 °C and a pressure of 30 bar in the competitive hydrogenation reaction. No conversion of 1-octene was noted in competitive reactions (mixed 1-octyne and 1-octene feed) but rather a gain of 1-octene throughout the 72 h time-on-stream. The performance of all catalysts was influenced by both the metal and support, where the latter impacted the overall acidity of the catalysts, thus affecting their long-term stability.
通过沉积沉淀法制备了负载在氧化铝上的银含量分别为2 wt%、5 wt%和10 wt%的催化剂，并在氢气气氛下进行活化。所有催化剂均通过布鲁诺尔-埃米特-泰勒（BET）测量、电感耦合等离子体发射光谱法（ICP-OES）、背散射电子扫描电子显微镜（BSE-SEM）、高分辨率透射电子显微镜（HR-TEM）、氢气程序升温还原（H-TPR）、氢化学吸附、热重分析（TGA）、红外（IR）光谱、X射线衍射（XRD）、拉曼光谱以及异丙胺（IPA）程序升温脱附（TPD）进行表征，并在连续活塞流固定床反应器中进行评估。通过HR-TEM分别鉴定出2 wt%、5 wt%和10 wt% Ag/Al₂O₃催化剂的金属纳米颗粒平均尺寸为4.5 nm、11.5 nm和21.1 nm。在140℃、30 bar压力的竞争加氢反应中，对于尺寸在10至15 nm之间的颗粒，1-辛炔的转化率达到99%，在长达24小时内运行稳定（此后转化率下降）。在竞争反应（1-辛炔和1-辛烯混合进料）中未观察到1-辛烯的转化，而是在整个72小时的运行时间内1-辛烯有所增加。所有催化剂的性能均受到金属和载体的影响，其中载体影响了催化剂的整体酸度，从而影响其长期稳定性。
