Effects of reduction conditions on the transformation of MoO₃ to MoO_x with large specific surface area have been investigated. The average valence number of Mo was an important parameter to determine the specific surface area of MoO_x, irrespective of the reduction conditions. Comparison of the specific surface areas at a certain average Mo valence, however, indicated that reduction at 773 K or below under a small H₂ flow rate was suitable for the formation of MoO_x with large surface area. The MoO_x possessed pores with diameters of 6–100 Å, and a good relationship was observed between the pore volume and the specific surface area. The reduction products were composed of the MoO_xH_y and/or Mo metal phases. The formation of Mo metal was suppressed under the reduction conditions suitable for the formation of large surface area MoO_x. Reduction in the presence of H₂O vapor was found to retard Mo metal formation, and to yield MoO_x with large surface area even at a high temperature and a large H₂ flow rate.

研究了还原条件对比表面积大的MoO ₃转变为MoO _x的影响。与还原条件无关，Mo的平均价数是确定MoO _x的比表面积的重要参数。但是，在一定的平均Mo价下比表面积的比较表明，在小H ₂流量下，在773 K或更低温度下的还原比适合于形成具有大表面积的MoO _x。MoO _x具有直径为6-100的孔，并且在孔体积和比表面积之间观察到良好的关系。还原产物由MoO组成_x H _y和/或Mo金属相。在适合于形成大表面积MoO _x的还原条件下，抑制了Mo金属的形成。发现在H ₂ O蒸气存在下的还原会延迟Mo金属的形成，并且即使在高温和大H ₂流量下也能产生具有大表面积的MoO _x。