Method of reducing NOx and particulates from internal combustion engines

Oxides of nitrogen are adsorbed onto the surfaces of, and particulates are trapped in, pores of channels (-) in a porous, interdigitated ceramic particulate filter that has relative rotation with respect to a gas inlet distributor. The distributor has a baffle or ribs that causes constantly flowing engine exhaust to enter the filter channels over a large portion of a revolution of the adsorption bed or the distributor, and causes constantly flowing syngas to thereafter pass through those passages during a small portion of each revolution. Either the inlet gas distributor or the filter bed may be rotated to distribute the gases. Dual, alternately regenerated filters may be used.