Effect of rare-earth promoters (Ce, La, Y and Zr) on the catalytic performance of NiO-MgO-SiO2 catalyst in propane dry reforming

Investigation of the Deactivation Behavior of MeMo/La2O3-Al2O3- and MeMo/Nb2O5 Supported Catalysts (Me = Pt, Ni, and Co) in Tri-Reforming of Methane

“…Moreover, the catalysts are reduced prior to the reaction. Thus, the NiO is strongly interacting with the supports, and well-dispersed Ni o species may coexist in the solids, according to the findings. ,, Hence, the reoxidation of the Ni species is the leading cause of the weight gain observed by TG results. The last stage at temperatures superior 750 °C may indicate the removal of heavy carbonaceous deposits, as shown by Ni-based catalysts tested in reforming reactions. , Since the oxidation of metallic nickel particles occurs between 300 and 750 °C with a small weight loss, the coke burned might be overlapped with the first oxidative event.…”

Enhancing CO and H2 Production in Propane Dry Reforming in Excess of CO2

“…Ye et al observed that titania-based catalysts showed strong chemisorption of CO 2 , which was retained considerably at higher temperatures between 600 and 1200 °C. The CO 2 adsorption over titania-based catalysts is illustrated in Table , and three CO 2 desorption temperature regions of basic sites were recognized over titania-based catalysts. − The first region is the weak basic sites of CO 2 between temperatures 35 and 325 °C, likely related to bicarbonate species, − while the stronger basic sites at higher-temperature CO 2 -TPD at 325–725 °C represented the bidentate carbonate intermediate with strong sites of CO 2 linked with the less oxide coordination state of titania-based catalysts and were likely related to basic surface oxygen anions. ,,− The highest temperature region >725 °C represented the oxycarbonate, which is attributed to strong basic sites and favors high-temperature decomposition. , Specifically, the addition of noble and transition metals to titania-based catalysts led to significantly more basic sites, indicated by the more than 1.7–2.7-fold increase in peak intensity between 35 and 725 °C incorporated with TiO 2 , compared to the original support. The amounts of basic sites decreased in the following order TiO 2 < Zr/Ti < Ir/Ti < Al/Ti < V/Ti, as shown in Table .…”

“…The CO 2 adsorption over titania-based catalysts is illustrated in Table 1 , and three CO 2 desorption temperature regions of basic sites were recognized over titania-based catalysts. 37 − 39 The first region is the weak basic sites of CO 2 between temperatures 35 and 325 °C, likely related to bicarbonate species, 38 − 42 while the stronger basic sites at higher-temperature CO 2 -TPD at 325–725 °C represented the bidentate carbonate intermediate with strong sites of CO 2 linked with the less oxide coordination state of titania-based catalysts and were likely related to basic surface oxygen anions. 38 , 39 , 43 − 46 The highest temperature region >725 °C represented the oxycarbonate, which is attributed to strong basic sites and favors high-temperature decomposition.…”

“… 37 − 39 The first region is the weak basic sites of CO 2 between temperatures 35 and 325 °C, likely related to bicarbonate species, 38 − 42 while the stronger basic sites at higher-temperature CO 2 -TPD at 325–725 °C represented the bidentate carbonate intermediate with strong sites of CO 2 linked with the less oxide coordination state of titania-based catalysts and were likely related to basic surface oxygen anions. 38 , 39 , 43 − 46 The highest temperature region >725 °C represented the oxycarbonate, which is attributed to strong basic sites and favors high-temperature decomposition. 38 , 39 Specifically, the addition of noble and transition metals to titania-based catalysts led to significantly more basic sites, indicated by the more than 1.7–2.7-fold increase in peak intensity between 35 and 725 °C incorporated with TiO 2 , compared to the original support.…”

“… 38 , 39 , 43 − 46 The highest temperature region >725 °C represented the oxycarbonate, which is attributed to strong basic sites and favors high-temperature decomposition. 38 , 39 Specifically, the addition of noble and transition metals to titania-based catalysts led to significantly more basic sites, indicated by the more than 1.7–2.7-fold increase in peak intensity between 35 and 725 °C incorporated with TiO 2 , compared to the original support. The amounts of basic sites decreased in the following order TiO 2 < Zr/Ti < Ir/Ti < Al/Ti < V/Ti, as shown in Table 1 .…”