Synthesis of Zr2 (PO4))(L) 2· H2O (ZPGly). The synthesis of ZPGly was achieved as reported in the reference [14]. In particular, 2.37 g (9 mmol) of N, N-bis (phosphonometyl) glycine (L) were dissolved in 93 ml of deionized water (0.097 M), and then 6 ml of phosphoric acid 1 M were add to this solution. 1.93 g (6 mmol) of ZrOCl2· 8H2O were dissolved in 20.4 ml of HF 2.9 M (59 mmol), molar ratio HF/ZrIV= 10. These two solutions were mixed in a 500 mL Teflon bottle and placed in an oven at 90 C. After three days the solid was filtered under vacuum, washed three times with deionized water, and dried at 60 C for 24 h. The empirical formula was Zr2P5O21C8N2H19 (PF= 816, IEC= 3.67 mmol/g) Preparation of ZPGly dispersion. 1g of ZPGly (1.23 mmol) was suspended in 108 ml of deionized water and then 22 ml of n-propylamine 0.1 M (2.2 mmol corresponding to 60% of IEC) were added under vigorous magnetic agitation. A stable dispersion was obtained. Preparation of Pd@ ZPGly composites. 14 ml of Pd (CH3COO) 2 0.05 M in acetone (0.7 mmol of PdII) were added drop by drop to 32.5 ml of the ZPGly dispersion (containing 250 mg of ZPGly) under vigorous agitation. The dispersion was left under magnetic agitation for 1 day (Pd@ ZPGly-1). Additional composites were obtained by increasing the reaction time to 7 days (Pd@ ZPGly-7) and to