Porous Ni-Ca-Al-O bi-functional catalyst derived from layered double hydroxide intercalated with citrate anion for sorption-enhanced steam reforming of glycerol

The sorption-enhanced steam reforming (SESR) technology may offer a mid-term if not near-term solution to mitigate climate change. A key requirement for the economic operation of SESR processes is the availability of highly effective bi-functional catalysts. Herein, we propose a citrate intercalated layered double hydroxide (LDH) strategy with in situ formation of carbon template to prepare the Ni-CaO-Ca12Al14O33 bi-functional catalyst featuring highly porous morphologies. The porous structure has inhibited the sintering of Ni and Ca species thanks to the physical isolation effect provided by citrate anion intercalation. The as-prepared Citrate-10NiCA2.8 displays a very stable performance for 35 reaction-decarbonation cycles in SESR of glycerol, during which H2 purity is retained over 98 % and only 30 % loss in sorption enhancement effect is observed, largely outperforming 10Ni-CA2.8 without citrate intercalation by 70 %. Moreover, the citrate anion intercalation strategy may also guide in designing materials derived from LDH for other high-temperature reactions.