c ac 2 wt ni 30 wt w x c preparation of w x c ac catalyst the process is similar to the example 1 the difference is only ammonium metatengstate is used to obtain the catalyst precursor without adding nickel nitrate and the carburization temperature is 800 u00b0 c in order to obtain w 2 c ac catalyst otherwise a higher carburization temperature of 850 u00b0 c is set to obtain w x c ac catalyst which is a mixed crystalline phases of w 2 c and wc 1 lt x lt 2 preparation of ru u2014 w 2 c ac catalyst impregnate the sample of w 2 c ac as prepared in embodiment 3 with rucl 3 solution then dry it at 120 u00b0 c and reduce it at 350 u00b0 c for 2 h in hydrogen the ru u2014 w 2 c ac 1 wt ru 30 wt w 2 c is obtained with 1 loading of ru and 30 wt loading of w 2 c preparation of co u2014 w 2 c ac catalyst the process is similar to the example 1 the difference is using cobalt nitrate instead of nickel nitrate to obtain the catalyst precursor in the catalyst the w loading is 30 wt and the co loading is 2 wt the catalyst of co u2014 w 2 c ac is obtained preparation of fe u2014 w 2 c ac catalyst the process is similar to the example 1 the difference is using iron nitrate instead of nickel nitrate to obtain the catalyst precursor in.