Direct Synthesis of Mesostructured Carbon-Metal or Carbon-intermetallic nanoparticles used as Potential Absorbents for Hydrogen Storage. Philippe Dibandjo 1 , Claudia Zlotea 2 , Roger Gadiou 1 , Fermin Cuevas 2 , Michel Latroche 2 , Cathie Vix-Guterl 1 1 Institut de Sciences des Matériaux de Mulhouse (IS2M) LRC CNRS 7228, 15 Rue Jean Starcky, BP2488, F-68057 Mulhouse, France. 2 Institut de Chimie et des Matériaux de Paris-Est, CNRS UMR 7182, 2-8, rue H. Dunant F-94320 Thiais, France. Introduction Recently, attention has been paid to porous carbons materials, owing to their large surface area, large pore, chemical inertness, and electrical conducting properties. In number of applications, such as adsorbents, catalyst supports, energy storage and conversion systems, is it essential to used micro and mesoporous carbons with well-tailored pore systems. For hydrogen storage application, these carbon materials have showed a low hydrogen storage capacity at ambient conditions [1,2]. One of the promising ways to increase hydrogen uptake at ambient conditions is to dope porous materials with transition metals [3]. The process used for the synthesis of the carbon containing metals nanoparticles is in two steps: (i) the synthesis of the porous carbon structure by the hard template route and (ii) liquid impregnation for the incorporation of metals in the porosity of the carbon host materials followed by the reduction treatment. This is a time- consuming and costly process. In this work, we try to reduce the synthesis process into a one step process. To reach the goal, a soft-template approach was used. An ordered mesoporous (carbon-metal) or (carbon- intermetallic) were synthesized and characterized by TEM, XRD and nitrogen adsorption apparatus for their physical and chemical properties. Their hydrogen adsorption equilibria and kinetics at 77K and 298K was evaluated. The metal or intermetallic loadings were fixed to 10 wt%. Experimental A-Synthesis of ordered Mesoporous Carbon The ordered mesoporous carbon was synthesized by the soft template approach following the procedures described in reference [4]. Resorcinol and phloroglycinol were completely dissolved in EtOH/water solution. HCl is introduced, and the solution was stirred for half an hour. Pluronic F127 was then added, and after it completes dissolution, formaldehyde was introduced. The solution was stirred for three days at ambient temperature, followed by filtration to separate the solid and the liquid. Then the solid was carbonized under argon up to 600°C for three hours. B- In situ doping of ordered Mesoporous Carbon by Pd, Pd1- xNix. In situ doping of metal or intermetallic into ordered mesoporous carbons was performed in a similar way as described above. For Pd precursor, a 10 wt% of an acid tetrachloropalladous solution in acetone was used and for Pd1- xNix, a solution of tetrachloropalladous acid, nickel nitrate and acetone was used. The precursor was added to the reaction mixture before the addition of formaldehyde and was kept stirring for half an hour, followed by the similar procedures adopted for the synthesis of ordered mesoporous carbon. The metal or intermetallic precursors were thermally cracked and become metal or intermetallic nanoparticles that were uniformly dispersed on the matrix during the carbonization procedure. Results and Discussion The TEM images of the carbon and Pd, Pd1-xNix doped carbons are shown in figure 1. It can be observed, small particles inside the carbon matrix. The particles are dispersed uniformly. The size of Pd clusters estimated by TEM is ranging between 2-6 nm and the size of Pd1-xNix clusters is between 6-20 nm. Figure1: TEM images of a) pure carbon, b) C-Pd and c) C- Pd0.66Ni0.34. The XRD patterns for the mesoporous carbons doped with Pd and Pd1-xNix are shown in figure 2. For both samples, the pattern displays five main broad peaks. The peaks at 2θ =23°, is common for the two samples and is attributed to the non- graphitized carbon, whereas the remaining four peaks can be indexed with the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) reflections of a fcc-structure. For the C-Pd, the cell parameter is a = 3.8907 Å which can be attributed to the Pd metallic particles. The C-Pd1-xNix displays a cell parameter of a = 3.766 Å. This value lies between those of Pd (a = 3.8907 Å) and Ni (a = 3.524 Å) confirming the formation of an alloy. By using these parameters we calculated the x the value to be x = 0.34. a) b) c)