P. Ticali, S, Morandi, G. Shterk, S. Ould-Chikh, A. Ramirez, J. Gascon, S.H. Chung, J. Ruiz-Martinez and S. Bordiga. Appl. Catal. A General (2023). PdZn/ZrO2 + SAPO-34 bifunctional catalyst for CO2 conversion: further insights by spectroscopic characterization