Unsupported, bulk phase palladium sulfide has been studied for the selective hydrogenation of acetylene. The sample underwent significant change during thermal pretreatments, the extent of which depends on temperature. Exposure to hydrogen at temperatures of 150 °C or above results in the loss of sulfur from the sample, primarily as hydrogen sulfide. As sulfur is lost, the sample is progressively transformed from a sulfur rich phase (PdS) to a sulfur lean phase (Pd₄S) via an intermediate phase (Pd₁₆S₇). Reduction at 250 °C produces a material, which contains Pd₄S as the surface phase, whereas reduction at 350 °C results in a largely pure Pd₄S phase. Thermal treatments which produce a Pd₄S surface display excellent catalytic properties. At complete acetylene conversion at 250 °C, ethylene selectivities of 82.8% and 90.0% were obtained under non-competitive and competitive conditions, respectively. Beneficial catalytic properties arise from the uniformity of Pd sites due to the crystal structure of Pd₄S along with electronic influences on the adsorption/desorption processes arising from sulfur neighbours. No indications of deactivation or significant deposition of carbon were observed over Pd₄S sample after 50 h on stream.

已经研究了无支撑的本体相硫化钯用于乙炔的选择性加氢。样品在热处理过程中发生了显着变化，变化的程度取决于温度。在150°C或更高的温度下暴露于氢气中会导致样品中的硫损失，主要是硫化氢。随着硫的损失，样品通过中间相（Pd ₁₆ S ₇）从富硫相（PdS）逐渐转变为贫硫相（Pd ₄ S ）。在250°C时还原会生成一种材料，其中包含Pd ₄ S作为表面相，而在350°C时还原会生成很大程度上纯的Pd ₄S期。产生Pd ₄ S表面的热处理显示出优异的催化性能。在250°C下完成乙炔转化时，在非竞争性和竞争性条件下，乙烯的选择性分别为82.8％和90.0％。由于Pd ₄ S的晶体结构，Pd位的均匀性以及硫邻域引起的对吸附/解吸过程的电子影响，产生了有益的催化性能。在运行50小时后，未在Pd ₄ S样品上观察到任何失活或大量碳沉积的迹象。