(EP1019713-A1)   NOVELTY - In a process for screening potential catalyst libraries reactant gas is passed in a passage (71) in a substrate (70) to an addressable catalyst test site (72) to form product gas plumes through which a radiation beam (77) is passed in a product zone (75) to form specified ions and electrons which are collected in real time by a microelectrode (78) in situ in proximity to the addressable site.    USE - In the screening for activity and selectivity of heterogeneous and homogeneous catalyst libraries.    ADVANTAGE - The process is broadly applicable, can be used to simultaneously, rapidly screen an entire catalyst library and can also be used to study operational lifetimes, resistance to poisoning, regeneration and loss of catalysts in tests or in full scale chemical plant processes. Detection methods in situ in the reactor use the high sensitivity, specificity and real-time features of resonance-enhanced multiphoton ionization (REMPI) in which pulsed and tuneable ionizing light sources are used to selectively photoionize desired reaction products without ionizing reactants and/or other background species. When reaction products are solids or liquids they can be ablated using a pulsed laser beam followed by selective photoionization of the products a suitable UV laser. The process can provide information on catalyst selectivity by detecting several reaction product species by using different light frequencies to sequentially generate specific ions of different products and the REMPI signals can then be converted into absolute concentrations by use of calibration standards. Internal calibration standards introduced with the reactant feed can be used to quantify reaction products.    (CN1281551-A)   NOVELTY - In a process for screening potential catalyst libraries reactant gas is passed in a passage (71) in a substrate (70) to an addressable catalyst test site (72) to form product gas plumes through which a radiation beam (77) is passed in a product zone (75) to form specified ions and electrons which are collected in real time by a microelectrode (78) in situ in proximity to the addressable site.    USE - In the screening for activity and selectivity of heterogeneous and homogeneous catalyst libraries.    ADVANTAGE - The process is broadly applicable, can be used to simultaneously, rapidly screen an entire catalyst library and can also be used to study operational lifetimes, resistance to poisoning, regeneration and loss of catalysts in tests or in full scale chemical plant processes. Detection methods in situ in the reactor use the high sensitivity, specificity and real-time features of resonance-enhanced multiphoton ionization (REMPI) in which pulsed and tuneable ionizing light sources are used to selectively photoionize desired reaction products without ionizing reactants and/or other background species. When reaction products are solids or liquids they can be ablated using a pulsed laser beam followed by selective photoionization of the products a suitable UV laser. The process can provide information on catalyst selectivity by detecting several reaction product species by using different light frequencies to sequentially generate specific ions of different products and the REMPI signals can then be converted into absolute concentrations by use of calibration standards. Internal calibration standards introduced with the reactant feed can be used to quantify reaction products.