Hydrolysis And Hydrogenation Conversion Of Cellulose Over Titanium,Zirconium And Tin Oxo Phosphate

It's a significant task of renewable energy to convert cellulose material efficiently. Metal oxo phosphate salt as a kind of unique solid acid catalyst, has a broad application prospect.This paper studyed the catalytic performance of the cellulose hydrolysis and hydrogenation conversion over titanium oxo phosphate?TiOPO₄?,tin oxo phosphate?SnOPO₄?, zirconium oxo phosphate?Zr OPO₄? and zirconium and tin oxo phosphate,?ZrSnOPO₄?x:y??.Solid acid catalyst TiOPO₄ and bifunctional catalyst Ru/TiOPO₄ were prepared. Basing on the optimization result of cellulose hydrolysis reaction over TiOPO₄, we studied the hydrogenation reaction of cellulose conversion to sorbitol over Ru/TiOPO₄. Experiments proved that a better sorbitol yield can be obtained under the reaction condition which the hydrogenation reaction temperature?453K? is slightly lower than the optimization hydrolysis temperature?463K? and the hydrogenation time is also a little lower than hydrolysis time. After optimization, we get the highest sorbitol yield of 77.6%, with the conversion 99.3%.We can draw a conclusion through various ratio of catalyst and cellulose experiments that the existence of the bifunctional catalyst Ru/ TiOPO₄ can make the substrate proceed hydrogenation in a great degree while it can reduce further degradation of glucose.The carbon recovery improve form 50% to 80%.Zirconium and tin oxo phosphate of different metal ratio were prepared. XRD and BET indicated that ZrSnOPO₄?x:y? became into amorphous form with the Zr percent increase. NH₃-TPD and Py-IR show that ZrSnOPO₄?2:1? had the highest amounts of total acid sites and the Br?nsted acid sites while Zr SnOPO₄?1:4? had the highest Lewis acid site. 31 P NMR proved that ZrSnOPO₄?2:1? had the highest amount of P-?OZr?2 and P-?OZr?3 bond,which make ZrSnOPO₄?2:1? had the the highest acid sites.This can futher explain the acidity characterization result.Using the zirconium and tin oxo phosphate as catalyst in the hydrolysis recation of cellobiose, we investigated the catalytic performance of zirconium and tin oxo phosphate.ZrSnOPO₄?2:1? had a glucose yield of 69.2% in the cellobiose transfer reaction while when used the ZrOPO₄ and SnOPO₄ as catalyst,the glucose yield is 55% and 53.9%. ZrSnOPO₄?2:1? has the most B acid site,which lead to the highest conversion. As the ZrSnOPO₄?1:4? has the most L acid site, it can the highest glucose selectivity of 91.4% in the cellobiose hydrolysis reacion.The result of catalysts reusability showed that,after using three times,the conversion of cellobiose reduced a large degree of 30%,which may cause by carbon deposit as the used catalyst didn't undertake calcinations treatment.