This chapter considers the nonequilibrium catalytic processes on the macroscopic level taking into account the interaction of reaction media with a catalyst. Such processes are the subject of thermodynamics of nonequilibrium processes and synergetics. Entropy production is one important quantity in the thermodynamics of irreversible processes. The application of the thermodynamics of irreversible processes often allows to connect the thermodynamic and kinetic parameters, in particular, to determine the rates of irreversible processes vs. outside conditions. The concept of affinity was utilized for the explanation of mechanisms of catalytic and noncatalytic processes. M. Boudart applied the concept of affinity to examine the direction of conversion in the system of complex consecutive reactions in catalysis and for chain processes. The chapter also considers examples of dissipative structures in heterogeneous catalysis. The first type of dissipative structure, namely, spatially periodic structures, has been widely studied with the help of X-ray and electron diffraction methods.