(US4774261-A)      Prodn. of methane or methane-contg. gas mixt. from an initial mixt. comprising CO, H2 and S cpds. comprises contacting the mixt. at 250-650 deg.C and 5-140 bars with a thioresistant catalyst compsn.. The catalyst compsn. comprises a Ce oxide support with Mo, V or W impregnated on it and opt. further comprises Co or Ni as an activity promoter.    Pref. the reaction is carried out at a space velocity of 100-15,000 hours (-1) and with a H2-to-CO molar ratio of at least 0.3 and the catalyst is of the formula X/CeO2, X/Co/CeO2, X/Ni/CeO2 or X/Co/Ni/CeO2 where X is Mo, W and V.    USE/ADVANTAGE -   Methane is synthesised with high selectivity from a gas mxit. obtd. by coal gasification without loss of catalyst by poisoning with S cpds.. (4pp)m    (US4833112-A)      A catalyst for the prod. of CH4 from Co, H2 and S cpds. has a general formula X/CeO2, X/Co/CeO2, X/Ni/CeO2, or X/Co/Ni/CeO2, where X is Mo, V or W.    The catalyst has a surface area above 10 sq.m/g, a total pore vol. of 0.15-0.5 cub. cm/g, a packing density of 0.5-0.25, an atomic ratio of X to Ce of 1/50-1/4. The atomic ratio of the activity promoter metal (Co and/or Ni) and the X metal is 0-1.    ADVANTAGE -   Stable selective catalysts are obtd. with good resistance to S cpds. (3pp)    (JP95005485-B2)      Methane or a methane-contg. gas mixt. is prepd. from a starting mixt. contg. CO, H2 and sulphur cpds., by contacting the starting mixt. at 250-650 deg.C and a press. of 5-140 bars with a thio-resistant catalyst comprising Mo, V or W and opt. an activity promoter chosen from Co and/or Ni, deposited on a CeO2 support.    Pref. catalysts correspond to the formula X/CeO2, X/Co/CeO2, X/Ni/CeO2 or X/Co/Ni/CeO2 in which X = Mo, V or W, and where the CeO2 has a BET specific surface of greater than 10 m2/g, esp. 50 m2/g, a total pore vol. of 0.15-0.5 cm3/g, esp. 0.3-0.4 cm3/g, a packing density of 0.5-2.5, esp. 1-2, an atomic ratio X/Ce = 1/50 to 1/4, esp. 1/20 to 1/7, and an atomic ratio promoter metal /X of 0-1, esp. 0.1-0.5. Pref. the reaction is carried out at a space rate of 100-15000, esp. 4750 hours power -1, a mol. ratio H2/CO of at least 0.3, esp. 1, a temp. of 300-600 deg.C, esp. 500 deg.C and a pressure of 30 bars.    ADVANTAGE -   The catalysts are resistant to deactivation by sulphur, have high activity, good long term stability, and good selectivity to prodn. of methane.