How can I enlarge the layout of the collection with Impulse theme ?

[Made4uo-Ribe]

Try this one:

#snize-search-results-grid-mode.snize-four-columns li.snize-product {
    width: 23% !important;
}
#snize-search-results-grid-mode li.snize-product {
        min-width: 0px;
}

Result:

I hope this work.