Pierfrancesco Ticali
@uni-kiel.de
Institut für Anorganische Chemie
Christian-Albrechts Univerisity of Kiel
RESEARCH, TEACHING, or OTHER INTERESTS
Spectroscopy, Catalysis, Physical and Theoretical Chemistry, Chemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Davide Salusso, Pierfrancesco Ticali, Dragos Stoian, Sen Wang, Weibin Fan, Sara Morandi, Elisa Borfecchia, and Silvia Bordiga
American Chemical Society (ACS)
In the last few decades, massive effort has been expended in heterogeneous catalysis to develop new materials presenting high conversion, selectivity, and stability even under high-temperature and high-pressure conditions. In this context, CO2 hydrogenation is an interesting reaction where the catalyst local structure is strongly related to the development of an active and stable material under hydrothermal conditions at T/P > 300 °C/30 bar. In order to clarify the relationship between catalyst local ordering and its activity/stability, we herein report a combined laboratory and synchrotron investigation of aliovalent element (Ce/Zn/Ga)-containing ZrO2 matrixes. The results reveal the influence of similar average structures with different short-range orderings on the catalyst properties. Moreover, a further step toward the comprehension of the oxygen vacancy formation mechanism in Ce- and Ga-ZrO2 catalysts is reported. Finally, the reported results illustrate a robust method to guide local structure determination and ultimately help to avoid overuse of the "solid solution" definition.
R. Matarrese, L. Castoldi, S. Morandi, P. Ticali, M.C. Valsania, and L. Lietti
Elsevier BV
Lidia Castoldi, Sara Morandi, Pierfrancesco Ticali, Roberto Matarrese, and Luca Lietti
MDPI AG
Pd-promoted zeolites (Y, ZSM-5, FER, SSZ-13) were prepared and characterized to analyze their properties as low-temperature NOx adsorbers. The samples were investigated by BET and XRD and by in situ FT-IR spectroscopy of CO and NO adsorption to probe the Pd sites and the nature of the adsorbed NOx species. The NOx adsorption/desorption performances at low temperatures were examined by microreactor measurements upon NO/O2 adsorption followed by TPD in the presence of water and carbon dioxide. It was enlightened that: (i) the zeolite framework influences the Pd dispersion: the smaller the zeolite cage, the higher the Pd dispersion, irrespective of the Si/Al ratio. Accordingly, the following Pd dispersion order has been observed, inversely to the zeolite cage size: Pd/SSZ-13 > Pd/ZSM-5 ~ Pd/FER >> Pd/Y; (ii) Pd is present as isolated Pdn+ species and in PdOx particles; (iii) the Pd dispersion governs the NOx storage capacity: the smaller the zeolite cage, the higher the Pd dispersion and the storage capacity; (iv) NO adsorbs mainly in the form of Pd nitrosyls and nitrates; (v) NO desorption occurs both at a temperature below 200 °C and in a high-temperature range (near 350 °C).
Pierfrancesco Ticali, Sara Morandi, Genrikh Shterk, Samy Ould-Chikh, Adrian Ramirez, Jorge Gascon, Sang-Ho Chung, Javier Ruiz-Martinez, and Silvia Bordiga
Elsevier BV
Pierfrancesco Ticali, Davide Salusso, Alessia Airi, Sara Morandi, Elisa Borfecchia, Adrian Ramirez, Tomás Cordero-Lanzac, Jorge Gascon, Unni Olsbye, Finn Joensen,et al.
American Chemical Society (ACS)
The valorization of CO2 to produce high-value chemicals, such as methanol and hydrocarbons, represents key technology in the future net-zero society. Herein, we report further investigation of a PdZn/ZrO2 + SAPO-34 catalyst for conversion of CO2 and H2 into propane, already presented in a previous work. The focus of this contribution is on the scale up of this catalyst. In particular, we explored the effect of mixing (1:1 mass ratio) and shaping the two catalyst functions into tablets and extrudates using an alumina binder. Their catalytic performance was correlated with structural and spectroscopic characteristics using methods such as FT-IR and X-ray absorption spectroscopy. The two scaled-up bifunctional catalysts demonstrated worse performance than a 1:1 mass physical mixture of the two individual components. Indeed, we demonstrated that the preparation negatively affects the element distribution. The physical mixture is featured by the presence of a PdZn alloy, as demonstrated by our previous work on this sample and high hydrocarbon selectivity among products. For both tablets and extrudates, the characterization showed Zn migration to produce Zn aluminates from the alumina binder phase upon reduction. Moreover, the extrudates showed a remarkable higher amount of Zn aluminates before the activation rather than the tablets. Comparing tablets and extrudates with the physical mixture, no PdZn alloy was observed after activation and only the extrudates showed the presence of metallic Pd. Due to the Zn migration, SAPO-34 poisoning and subsequent deactivation of the catalyst could not be excluded. These findings corroborated the catalytic results: Zn aluminate formation and Pd0 separation could be responsible for the decrease of the catalytic activity of the extrudates, featured by high methane selectivity and unconverted methanol, while tablets displayed reduced methanol conversion to hydrocarbons mainly attributed to the partial deactivation of the SAPO-34.
Adrian Ramirez, Pierfrancesco Ticali, Davide Salusso, Tomas Cordero-Lanzac, Samy Ould-Chikh, Christian Ahoba-Sam, Aram L. Bugaev, Elisa Borfecchia, Sara Morandi, Matteo Signorile,et al.
American Chemical Society (ACS)
The production of carbon-rich hydrocarbons via CO2 valorization is essential for the transition to renewable, non-fossil-fuel-based energy sources. However, most of the recent works in the state of the art are devoted to the formation of olefins and aromatics, ignoring the rest of the hydrocarbon commodities that, like propane, are essential to our economy. Hence, in this work, we have developed a highly active and selective PdZn/ZrO2+SAPO-34 multifunctional catalyst for the direct conversion of CO2 to propane. Our multifunctional system displays a total selectivity to propane higher than 50% (with 20% CO, 6% C1, 13% C2, 10% C4, and 1% C5) and a CO2 conversion close to 40% at 350 °C, 50 bar, and 1500 mL g–1 h–1. We attribute these results to the synergy between the intimately mixed PdZn/ZrO2 and SAPO-34 components that shifts the overall reaction equilibrium, boosting CO2 conversion and minimizing CO selectivity. Comparison to a PdZn/ZrO2+ZSM-5 system showed that propane selectivity is further boosted by the topology of SAPO-34. The presence of Pd in the catalyst drives paraffin production via hydrogenation, with more than 99.9% of the products being saturated hydrocarbons, offering very important advantages for the purification of the products.
Pierfrancesco Ticali, Davide Salusso, Rafia Ahmad, Christian Ahoba-Sam, Adrian Ramirez, Genrikh Shterk, Kirill A. Lomachenko, Elisa Borfecchia, Sara Morandi, Luigi Cavallo,et al.
Royal Society of Chemistry (RSC)
The tandem process of carbon dioxide hydrogenation to methanol and its conversion to hydrocarbons over mixed metal/metal oxide-zeotype catalysts is a promising path to CO2 valorization.
Mattia Giuliano, Maria Carmen Valsania, Pierfrancesco Ticali, Enrico Sartoretti, Sara Morandi, Samir Bensaid, Gabriele Ricchiardi, and Mauro Sgroi
MDPI AG
Ageing of automotive catalysts is associated to a loss of their functionality and ultimately to a waste of precious resources. For this reason, understanding catalyst ageing phenomena is necessary for the design of long lasting efficient catalysts. The present work has the purpose of studying in depth all the phenomena that occur during ageing, in terms of morphological modification and deactivation of the active materials: precious metal particles and oxidic support. The topic was deeply investigated using specific methodologies (FT-IR, CO chemisorption, FE-SEM) in order to understand the behavior of metals and support, in terms of their surface properties, morphology and dispersion in the washcoat material. A series of commercial catalysts, aged in different conditions, have been analyzed, in order to find correlations between real and simulated ageing conditions. The characterization highlights a series of phenomena linked to the deactivation of the catalysts. Pd nanoparticles undergo a rapid agglomeration, exhibiting a quick loss of dispersion and of active sites with an increase of particles size. The evolution of the support allows highlighting also the contribution of chemical ageing effects. These results were also correlated with performance tests executed on synthetic gas bench, underlining a good correspondence between vehicle and laboratory aged samples and the contribution of chemical poisoning to vehicle aged ones. The collected data are crucial for the development of accelerated laboratory ageing protocols, which are instrumental for the development and testing of long lasting abatement systems.
Lidia Castoldi, Roberto Matarrese, Sara Morandi, Pierfrancesco Ticali, and Luca Lietti
Elsevier BV